Miami Condo Collapse: Engineers Baffled By Mystery Column

[@russlehman2070]

The more I learn about Champlain Towers South, the more I think that the true mystery is not why it collapsed, but how it managed to stay standing for 40 years.

[@jeffostroff]

yes good point!

[@MajorCaliber]

The building bravely resisted the stoo-pidity of Duh HOA, but eventually the patient succumbed.

[@johnbergstrom2931]

It's like reading about the Titanic and exclaiming, "Jesus, those poor bastards were doomed!"

[@jeffostroff]

@@johnbergstrom2931 This ship caaaaaant sink!

[@hirisk761]

@@jeffostroff it's made of iron. I assure you it can AND WILL in 2 hrs maybe more

[@mikedean4236]

The rebar sticking up out of the ground in the mystery location could have come from the column that sat atop the h-bar, which separated from it and then was "pile driven" into the concrete floor. There is no concrete visible, which could be because it was pulverized as the column was driven through the concrete slab.

[@matthewbeasley7765]

That would be my guess too. It's impaled through the floor.

[@jeffostroff]

Your hypothesis comes up a lot from boatloads of people about that column. I don't think it's possible because if it had slipped off it would not likely have come straight down where the mystery column is which is only about two feet away from the HP. Also if it had impaled the floor there should be damage all over the concrete there and there is none where is the crater? So where else could the column come from? So far my prevailing theory is that somebody started to build that column sometime after Fiorella shot her video in July 2020. however I could find no permits for it

[@ke6gwf]

@@jeffostroff if you actually look at your own video, at 13:50 you can clearly see the edge of the floor slab where the penthouse 5th column punched through it. It's filled with water so if you don't look closely you may think it's the slab, but you see the broken edges around the rebar. It's also exactly where the penthouse column would have been if it dropped straight down.

[@dannyswank]

@@jeffostroff You just proved that the penthouse column was punched through the slab. Stop looking for conspiracies where there are none.

[@jeffostroff]

@@dannyswank It's not a conspiracy stop trying to let me into your conspiracy theory crowd

[@raouliii]

My guess is that column started on the 1st floor and punctured the floor of the garage during the collapse. When the H beam shifted during the initial collapse, the mystery column had zero support and helped initiate the collapse of the eastern section of the building. Two observations to support the puncture: There doesn't appear to be any residual concrete in between the rebar of the mystery column at the floor level like the other columns and a puncture would be the reason water seems to be rising through the floor at that location.

[@johnbergstrom2931]

No, there would have been WAY more damage to the slab in that case. No way it went in that neatly...

[@jeffostroff]

There would have been a lot of damage to the basement floor

[@MajorCaliber]

@@johnbergstrom2931 I dunno... remember, it's NOT over a piling cap, and look at how CLEAN the punching shear failures are in *every other instance,* here at CTS--not one single example of the textbook 45-degree "crown" remnant of slab on ANY of the columns, both the heavily-loaded columns within the building envelope, and the lightly (or so they thought) loaded columns under the pool deck. NOT ignoring the fact that "mystery" column in this scenario was NOT attached to on-grade slab, but instead would've had a "running start", and "speared" through, but I've just never seen that modeled... yet.

[@johnbergstrom2931]

@@MajorCaliber Ok, then just look at the simple physics. When the east wing started to collapse, slightly to the southwest, those columns were not just magically freed from their rebar connections, accelerated and hurtled, perfectly vertically, towards the ground at a speed greater than terminal velocity to make a neat perfect hole in a brittle material. That's what happens in cartoons... No, the columns followed the motion of the structure, began to rotate and wound up pancaked into a pile, in between the slabs.

[@andypandy8139]

Agree. Maybe the rebar rods had very similar bottom lengths and happened to strike the garage floor pretty much at the same time with all the weight from the 14 floors above that may have allowed the column that started on the first floor to punctured through garage floor neatly. There has to be some WTF's when a building of that size crashes to the ground in seconds. Physics can be hard to conceptualize when you are dealing with tons of different materials bumping into each other on the way down to the ground. Kind of like what happens during a hurricane , there are a lot of similarities between each, but none are exactly the same. It could have also been aliens that placed it there, but I will leave that discussion for another time.

[@siamsurf]

My theory: That mystery column was actually the one that started on top of the H-beam, and it impaled the ground, when it slid off the H-beam. It would also explain the water which pools around the mystery column.

[@jeffostroff]

most common theory so far

[@silentferret1049]

@@jeffostroff A thing to note is the 4 main columns have concrete still on the base connecting to the ground and that mystery one is pretty clean. Only way to know if its impaled rebar is to pull one of them. Who knows how they were before clean up happened. Either way its odd and a beam having to shear off to leave straight enough pieces of rebar to straight out impale the floor like that is pretty slim chances. If it did then there should be some cracks in the floor there which would be the water problem and in the photos be hidden under that water. My playout is the mystery beam sheared off leaving the rebar almost fully surrounded my the concrete and it slammed into the ground driving the rebar but breaking the surrounding concrete then the mystery beam shifted back towards the H beam. Because you look how the rebars are placed on that mystery beam and they seem so random compared to the others around

[@kevinverduci7600]

That's a good theory but I am going to play The devil's advocate how would that account for the rebar if it was just beam spearing The ground? I'm no engineer but I am a union carpenter Foreman so I have a fair amount of knowledge in construction stuff and I can't understand the rebar that had to be put there on purpose.

[@PreservationEnthusiast]

@@jeffostroff There was no column there or added there. There is no residual concrete in the rebar like all the other columns. Also the the reinforcement is really heavy, unlike all of the other columns. The only thing I could think of is impalement of some structural element above during collapse. It almost looks like someone is having a joke and added extra rebar in the hole. I can't see why it is so heavy.

[@jeffostroff]

@@PreservationEnthusiast Yes even the impalement theory has problems as well because those rebarters are sticking straight up out of the floor but yet the vertical position of the column over where the impaled area is It's off about 5' So this column falling at an angle could not possibly impale the floor in my opinion

[@fraidykat]

We know it came from somewhere, and we know this column lines up with where the column above the H used to reside. This is now in the basement floor right where we would expect it to be if the H shifted towards the collapse area. When M11.1 fell, it created a void in the center of the structure that then pulled the H beam towards Mll.1's main pillar victim. You can see the columns that remain under the H show the H has shifted towards the initial collapse point. That "mystery column" is the ground floor column that when all the way up to the penthouse suite. Instead of staying connected to the H, at some poin tin the collapse sequence the column unhinged itself form the H and instead drove into the basement floor, with the weight above the column and the force of gravity together acting as a hammer to drive that column into the basement floor. Yes, there's a very good reason why it is now leacking - it's punched through the ground floor. That's it.

[@Phoenix-jw1mn]

To be honest, the best way to debunk whether this was an added column or a punch through would be if investigators simply asked the surviving residents if there were columns added recently and if there were any added in that area and in the way of traffic. Adding columns on the side and out of the way might not make some people notice an addition but putting one in the way of traffic, especially right near the entrance would make some heads turn and some complaints filed. Witness testimony, in this case, will give us our best understanding if there was an actual structure there before the fall, speculation can only get us so far after the fact.

[@johngreydanus2033]

Ask the residents? How about asking the building management? You know, the people that were coordinating the 40-years inspection and repairs? They have records and I'm sure that has been looked into.

[@jeffostroff]

I would like to tlak to anyone who survived, and HOA people as well, and managers, and maintenance workers

[@mixedupmenopausaladhd3999]

Probably all kinds of NDAs/gag orders while litigation underway

[@k53847]

@@mixedupmenopausaladhd3999 NDA's don't apply when you are subpoenaed by a court. Which is what NIST can do. So we'll hear, but maybe not for another year or two.

[@johnbergstrom2931]

Maybe the surviving residents (most lived on the west side) entered/parked/exited on the other side of the garage and didn't really have any need to go over to the east side... Maybe they don't know. Maybe the illegal work was concealed by a tarp or a fence or some kind of enclosure. Who knows? Maybe some day we will!

[@RobbieHatley]

I see exactly what happened here, Jeff. Here are 2 big clues: Clue #1: Note that in the diagrams, the H-beam is about 20m from the ramp. But note that in the video of the site post-collapse and post-cleanup, the H-beam is only about 10m from the ramp. The only way that could have happened is, the H-beam fell downward and northward at a 45° angle. But would you expect anything different? The H-beam was perched on top of large columns, and they were unlikely to just crumble, so they probably fell over instead, causing the H-beam to move downward at 45° instead of 0°. Clue #2: Where on the diagrams do we see a row of 3 columns in a N-S row? At O4, O6, O8, about 10m north of the original location of the H-beam, _again_ implying that it fell downward and northward at a 45° angle. In other words, this building didn't crumble, it parallelogrammed. It sat there for 40 years like a house of cards waiting for something to give it a nudge. The pool deck collapsing was that nudge, causing it to fold in on itself.

[@jeffostroff]

Unfortunately, you are wrong in both cases the H beam is resting exactly where it shows on the diagram I don't know why you think it is further away. Also those columns you show in 04, 06 and 08, are clearly shown on the floor of the garage right next to the beam in some of the photos. Remember the column I pointed out that is sticking halfway up the parking spot #17, which would have been Fiorella’s parking pace if she bought that unit? That is 06, and the column with the red stripe on it is 08. Note how O6 and O8 are close together, then look at the photos near the ned showing them still there. Those are NOT what the H-beam was resting on, only O8.

[@johnbergstrom2931]

Also, there was not even close to enough lateral force to move that 65,000+ pound H beam away at a 45 degree angle during the 3-5 seconds it took for the east wing to collapse.

[@davesmith5656]

@@johnbergstrom2931 ----- The ghosts of the Egyptian pyramid builders put the mystery column there just to mock us.

[@roygradidge7538]

I agree with Robbie, that H beam does not look like it is in the proper position, almost as if its moved a bay from its original position and basing this on the position of that red line that you say is the extent of the parking bay.

[@Iconoclasher]

To quote Sherlock Holmes (or Mr Spock) “When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth.” There is a mystery broken column where there isn't one on the video. My first impression was a chunk of column coincidentally landed there with its rebar sticking up. Later in the video, a close up kinda dispelled that theory. Jeff, I know you disagree with Robbie but the H beam coming down on an angle is the only explanation. Nothing else can account for the discrepancy. If the building dropped straight down I'd think more columns would have remained standing. Since they all appear to be broken off at the base its a fair probability the garage "ceiling" (along with the building) came down on an angle that displaced the H beam. Also the building didn't just drop straight down. It came down in sections. That alone would have made the ceiling collapse unevenly. The physical, tangible evidence is right there. Can't be ignored.

[@LakeNipissing]

Jeff, your tool review / sale videos are nice, but this is the technical stuff I have been waiting for (and I am sure others too).

[@jeffostroff]

Yes, I've been doing a huge amount of the tool stuff lately simply because this is our busiest time of the year with the Black Friday tool deals. I do like to do a lot of how-to's and of course continuing the coverage of the condo collapse in the engineering analysis associated with that. You will see a mixture of this on the channel. make sure you go back and look at a lot of our how TOS you'll see a lot of pretty in-depth engineering stuff there and clever fixes to get out of some really tough situations that

[@kentinnovatec3336]

The mystery column was: 1. added later: Wrong. There is no visible concrete around the rebars. In addition, the rebar doesn't appear new. 2. pushed through from 1st floor column: Correct. You can see the skid mark at the side of the H-beam from the column at the 1st floor falling down at 13:48. The rebar made it through without cracking the floor because the basement floor is very solid.

[@jeffostroff]

There is no physical concrete because it was either removed by the collapse of the building, or the democrats when they removed everything. Look at all of the other columns sticking up out of the floor ofloor of the garage all over the place, all you see is just the rebar wires. So you're causality was a little off there just because there's no concrete between the rebar doesn't mean there wasn't any at some point in time period but I do believe if this column was added, it was put up some time in the last 12 months before the collapse.

[@manikaggarwal2018]

Kent , you are correct this was put there by NIST to complete the picture of the columns

[@manikaggarwal2018]

@@jeffostroff I don’t agree with your language and your comments

[@kentinnovatec3336]

@@manikaggarwal2018 Thanks. My guess was based largely on the resemblance between the mystery column and the surrounding steel bars.

[@rafaelshumaker1883]

My first thought is that it is the upper support beam. It is clear that the H beam structure pulverized the tops of the 4 columns it was mounted on. The H beam structure is sitting slightly to the north and west of its original position, by a few inches. Once the H beam came to rest on the basement floor, the extra beam above still had its own momentum, plus whatever weight was resting on it. From the looks of it, my guess is that the extra support beam buckled maybe a few feet above its own bottom, and got pushed in a northeast direction. With the concrete crumbled to pieces and powder at the buckle point, rebar formed tight curves. The rebar may not have much strength on its own. But with who knows how many tons pushing hard and fast on the unbroken part of the beam above the buckle, the tightly curved rebar may have focused all that momentum onto a single point, creating an initial crack in the basement floor. Then the beam that is still coming down with incredible force, focused in a tiny area, punches right through the now cracked concrete floor, like a needle. If you look at the H beam, where the upper beam had been resting, you see a considerable depression, along with what looks like the aftermath of rebar having been ripped out of the eastern face of it. But I'm not an engineer, at all. So, this is the guess of a total amateur.

[@jeffostroff]

You are not far off what we are unsure of is if the floating column impaled the floor or not. There is not heavy damage to the floor.

[@GeneralKenobiSIYE]

@@jeffostroff Except there is. The area around the slab shows a clear irregular depression at the 4:42 mark. It's not easy to see as there is water pooled there so it looks flat. The column is also not exactly in line with the other two. The bottom of the cross beam of the H beam also shows no damage where the column would have been positioned had it actually been there. Retrofitting a column there would have made zero sense as it would not have added much if anything to the structure other than to obstruct a main thruway.

[@MrBmxbrawler]

@@jeffostroff no heavy damage at all. There is no way those pieces of steel punctured themselves through the floor without blowing the floor entirely out of place

[@jaysonpida5379]

Tend to agree with the 'punch-thru' explanation > There's no concrete cladding around it's base as all the other parking garage 'pillars' exhibit and there does appear to be a 'punch-through' hole that has just been filled with all the muck from the clean-up and is still leaking the ground-water. The reason all those re-bar make it appear to be a larger column then what's in the plans is that it's all that vertical column rebar coming down trying to ram itself through the hole -a true pile driver. Wouldn't be surprised if that rebar goes down 20+ feet.

[@getx1265]

Thanks Jeff for the additional, continuing info regarding the collapse.

[@jeffostroff]

You are very welcome

[@robertmorley3743]

The mystery column is the remnants of the column that sat in the middle of the "H". As the collapse occurred, the column was pushed off the "H" driving it downward off the "H," penetrating the slab. The screen grab shows no signs of concrete connection to the slab. It is penetration of the rebar with compressive destruction of the concrete between.

[@robertmorley3743]

Punching shear does not exert great lateral loads on the base of the columns, which is why you still see every column with concrete between the rebar. The mystery column is different from every other. I think the level of the slab appears even around the rebar of the mystery column, because it is sediment carried by the flooding water into the slab penetration "crater" - you are not seeing slab, you are seeing sand the same level as the slab.

[@jeffostroff]

You forget that there is zero damage on the floor where there should have been craters or something else if it had impaled into the floor but there is no damage. These rebar rods look like they were intentionally built up out of that concrete floor like it was done by somebody in the last 12 months, since Fiorella shot her video inside the garage in July 2020, showing no column exists where that mystery column is.

[@robertmorley3743]

@@jeffostroff The screenshot of the Mystery Column is post drainage of the site by pumps. Notice the accumulation of the east facing south portion of the "H" The crater around the penetration through the slab by the rebar is filled with the same sediment, which was moved around during the draining process.

[@excellent_name]

@@robertmorley3743 do you think that the rebar would have stabbed in to the garage floor firmly enough that it would not have been dislodged/cleaned during the excavation process?

[@johnbergstrom2931]

@@robertmorley3743 And the 'magic penetrator' column spaced itself with perfect alignment in the 'O' row of columns, and perfectly spaced itself right in the exact center between the columns holding up the H beam???? Nature don't work like that, son. People do, though... It was put there by human hands. Your scenario is a fantasy. Put down the crack pipe and come back to reality, Bobby.

[@ellenkass9410]

Thanks Jeff. This gets curiouser and curiouser. 🏜👩‍🦳🌻🌞

[@jeffostroff]

Glad you enjoyed it It's like a Pandora's box every piece of evidence we ever find just opens up 100 more questions instead of answering the one that we have at hand.

[@vsiegel]

I think it is possible that the mystery column was impaled into the concrete ground. If we assume the H-beam gets out of the way, and the column that goes to the top of the building stays straight and builds momentum while dropping one building level, it has a lot of energy when it touches the ground. It has a lot of compression load, and not much reason to burst sideways. It is easily much stronger than the concrete ground of the parking garage.

[@jeffostroff]

It might be, but there is no damage to the floor.

[@dascandy]

I think the 11 floor beam on top of that H got shoved aside and impaled itself there by going down a floor and being pushed by 11 more floors. Was that the reason of collapse or secondary?

[@vsiegel]

@@dascandy I am not sure the floors are relevant, I think it is the column itself. The floors attached to the column are somewhat elastic, there is a delay until they contribute to the load on the lower end, after contact. The delay for the moving column itself is much shorter, I think it depends on the speed of sound in concrete, which is much higher than in air. I would think if the column is still straight up at the time, the full load applies after the time a shock wave travels to the upper end of the column, or up and down. Along the length of the column, the speed of sound is 3700 m/s.

[@vsiegel]

@@Randrew I found it almost spooky myself until I came up with that explanation, I could directly see it is there, and almost as directly that it can not be there. I did not see the option that it was placed there recently because the building had already started to fail, which is still possible. I could totally understand the term mystery column, without expecting anything irrational.

[@GeneralKenobiSIYE]

@@jeffostroff Except there IS damage. Pooled water makes it hard to see. All of the other columns, there is concrete around the base, whether broken in chunks between the rebar or even still intact. With this column there is none and the area around the rebar poking out of the slab is depressed. It's lower in and around the rebar. There is a pretty clear and irregular depression around the rebar. The column is also halfway out of line with the other two columns. It's just difficult to see it from the angle. Residents would have also bitched up a storm if they had suddenly added a column in the middle of the thruway. Forces exerted by so much weight falling that a broken column from above could have easily been driven into the slab. It looks like it isn't even the only one. It looks like there is also another on the other side of the H beam. Such a thing would not be unique either.

[@ws_m]

The mystery column defiinitely looks like a different animal than the others. It seems to have a different layer concrete around the base and different rebar. Another fine video further explaining the many facets of this disaster. Thanks again, Jeff.

[@jeffostroff]

Yes good point about the concrete!

[@MostlyLoveOfMusic]

Yeah there is no stub of concrete at the base of the mystery column. Perhaps this mystery column was installed in the very recent past after cracking observed in the H-beam? There would not be a strong bonded connection between the old concrete and the newly poured concrete

[@JohnnyMotel99]

@@MostlyLoveOfMusic It's not in line with the middle part of the H beam, it looks to be in line with the two support columns. A column just going from the car deck to the ceiling slab??? Plus it's slap bang in the middle of the 'roadway', are these roadways wide enough for a large SUV to go around a large column? It's a wonderful mystery that will come out in due course.

[@MostlyLoveOfMusic]

@@JohnnyMotel99 you're right, it doesn't add up. But there are definitely engineers involved who know the answer to this and it will be revealed during the legal proceedings

[@eugeniustheodidactus8890]

*Ditto!* Wish I had read your comment before posting my long reply! Lol.

[@willbob8532]

Great job love your videos

[@jeffostroff]

Glad you like them!

[@edl653]

I find it incredible that there are trolls in this type of serious, investigative site. To all, once you see criticism that is not seriously critical and explanative, but instead is abusive and insulting, you know the source is just a troll that needs to be ignored. Personally if possible I would block and delete worthless and mean spirited comments. - Jeff, keep up the good work!

[@jeffostroff]

He has enough immature minions who follow him under numerous names and they just pop up new names

[@jenniferbeyer6412]

The theory about the column pile driving itself into the basement floor makes sense and answers the questions of the collapse. Also why there is water in that area. It punched through to the water table.

[@billj5645]

I posted when I first viewed this video and now I'm back for an update. I could have done this earlier but I'm lazy and my real engineering job keeps me plenty busy. I've spent a lot of time walking construction sites and counting columns to determine where I am on the plan so it wasn't any different looking at your video at 13:29 and matching up columns with the structural plan. At that time I agreed that these 3 beams fell pretty much straight down. At 1:00 in your video you show a view of the site looking straight down but the site wasn't completely cleared. Stumbling around youtube I found another aerial photo showing the site completely cleared. It was pretty easy for me to put a screen capture of that photo next to the correct structural plan and within the accuracy of the low resolution youtube video it was easy to see that beams 34 and 35 were in their correct plan location as if they fell straight down, not to one side, not at a 45 degree angle, but straight down. That doesn't solve the mystery of what that "thing" is on plan and I already posted my ideas on it, but I 100% agree with you that the 3 large beams are still in their exact plan location.

[@jeffostroff]

Yes I estimated the H-Beam dropped off the top of the 4 support columns and fell 12" north of the columns

[@johnbergstrom2931]

Well, not technically "straight down". The centerline of beams 33 & 34 are displaced from the centerline of the columns they rested on. Kind of hard to measure in this video, but I figure the east side of the H beam moved about 2 feet (the beams were 24" wide), while the west side moved about 6 inches. But yeah, the 45 degree theory is utterly ridiculous. BTW, beam 35 is the center section. 33 & 34 are the legs.

[@Tom05181961]

Boy, the court cases are going to be staggering for this disaster. I say this as a retired litigation paralegal.

[@johnbergstrom2931]

Yeah, in theory, but who do you sue? The developer is dead, the architect is dead, the building inspectors dead, a lot of the construction workers who built the thing are probably deceased. The condo was owned (and maintained) collectively, not like there was a rich company who decided to effectively not do required maintenance for 40 YEARS... They can't really sue themselves, or sue other surviving residents who didn't have enough information to know how dire the problem was, and didn't really have much say one way or the other. All they can do is split up the money from the sale of the property.

[@jeffostroff]

I think it is somewhat unfair but even the engineer Morabito who was there to help and was the smartest one of anybody whoever touched the building is being sued even though I don't think he did anything wrong. He's the one that told him that the entire pool deck has to come out and be redone.

[@ChiTownDude]

There's no "deep pocket" to sue. As a litigation paralegal, I would have thought you would know better.

[@MajorCaliber]

Yep, what the first 3 responders said. Plus the judge in charge is a no-nonsense jurist who *moves things along* and I respect him for that. He quickly assigned a Special Master, and is committed to selling the lot ASAP, distributing the proceeds equitably, and putting this matter to rest. Miami-Dade Circuit Judge Michael Hanzman appears to have ZERO tolerance for cranks, conspiracy theorists, and frivolous lawsuits. He's even limited what the lawyers involved can charge, saying they shouldn't expect "anything close to what you make on personal injury cases!"... LOVE IT!

[@k53847]

@@johnbergstrom2931 The city is the deep pockets in this case. The action of head of the building dept seem pretty irregular. "Your building is in fine shape". Crash.

[@southronjr1570]

As a professional firefigter of over 20 years I might have a good idea how the "column" appeared. I have on numerous different occasions seen structural members "pile drive" themselves into the ground and through slabs due to collapse. My ,somewhat educated, guess would be that he column hat was supported by the H beam broke off close to the H beam and proceeded to drive itself into the foundation slab during the collapse. I once saw a 4x4 wooden post do something similar through a basement foundation slab due to a structural collapse and have seen it also with vertical I beams in investigations. I am not the only one with this conclusion either by the comments section I glossed over before commenting

[@jeffostroff]

Well the problem is this mystery column is 5 feet from the H-Beam so how can c olumn falling at that angle be straight up in the floor, and also no damage to the floor?

[@southronjr1570]

@@jeffostroff The only way to answer that would have been able to see the column before the demo crews cleaned it up. The equipment could have pushed the rebar into a different angle than it originally came to rest in, or it could be from another column entirely that found a void to go through and drive itself in. Without seeing the debris as it was uncovered, it will be impossible to say for sure either way. My guess is that when the report comes out it will either be mentioned or completely explained and with the litigation and public interest, the invetigators will be very thorough and we will get the answer then. It plainly isn't there in the video pre collapse and so it had to have come from somewhere and my original post is my guess as to how it happened. I might add that even the best of investigators dealing with engineering anomalies still have to do a whole lot of guessing to figure this stuff out without concrete video proof showing the entire event.

[@TRAXRIPPER]

When it collapsed that one from the lobby could have been pile driven into that spot. The concrete around the rebar would have shattered when it got the slab but the rebar easily could punch right into the slab quite deep actually without breaking the slab to much. It would have had like a 16 foot free fall before it pounded in and did impale the slab. The water around it is blocking your view of the slab to inspect the rebar to see what the slab looks like. That will tell you if it's mounted or pile driven in from lobby level. That is what my guess is. Keep us posted when you find out! Thanks for the info and updates! As an iron worker I've worked with many masons and welded tons of mason anchors on galvanized lentils for mason attach points and spent many of hours with a damn vibrator during slab pours to help out sticking that thing under double mat bar to get out air pockets and settle the slab for finish when it's a dry or "hot" mix pour meaning get it out of the mixer before the only way to get it out of the mixer is drive the truck to a bunch of guys with ear plugs safety glasses and big ass Jack hammer air chisels! FUN FUN FUN! 💩💩💩💩💩💩💩

[@johnbergstrom2931]

It wasn't. Watch the video again and pay close attention at 13:47. Jeff zooms in and you can see the rectangular outline of where someone cut that slab, installed a footing & rebar and closed up the hole again. You can see some of the concrete 'slop' that got on the rebar. There was no column formed and poured around that rebar yet; if there was, it would look like all the other destroyed columns. Construction of that column was 'in process'.

[@jamie.777]

I was a union laborer in Boston for a concrete flatwork and wall sub contractor. The iron workers and concrete "dudes" earn there pay checks.

[@jamie.777]

@@johnbergstrom2931 I see it! I used to drill holes for dowels to connect old concrete with new fill in.

[@ricka1799]

@@johnbergstrom2931 My first thought Sherlock..

[@lisastiles1408]

@@johnbergstrom2931 On the technical side, my greatest expertise is in power generation, not structural loads, but the second half of my career encompassed accident analysis, equipment reliability , performance improvement, aging management, human performance, and training. My first instinct was that it was a temporary modification meant to “make do” until the squabbling about who, when, and for how much were they going to spend to just fix the damage from and to repair pathways of. water intrusion. Your thought that it was started but not completed would explain the as-found condition.

[@erichaynes7502]

Hey Jeff, everybody; I'm gonna have to dig it up but a few weeks ago there was a very good YT video that showed in detail design flaws that doomed this building from the start. It was about 10 minutes long the narrator had a foreign accent with great animation. I'll try to dig it up and post it soon as the guy really seemed to know his stuff.

[@jeffostroff]

Mike bell, I think

[@billj5645]

@@jeffostroff There was another video by an actual structural engineer who did some analysis of the building. He got some criticism and hasn't posted anything since.

[@billj5645]

Jeff actually addressed some of these items in one of his videos.

[@MajorCaliber]

Just noticed, during the drone overflight in the very last 10 seconds of this vid, they're doing some serious "batter pile" type shoring of the retaining wall, but only on the Collins Ave. portion... I guess the consequences of Collins sliding into that pit means "failure is NOT an option"..

[@jeffostroff]

Yes a concern earlier on was that they were worried Collins Avenue would collapse into the site. Now they've added a lot more showing polls up against the wall

[@billj5645]

Allen had already pointed this out to the city. Having the walls on the west side fail and let part of the street and sidewalk fall into the pit would not be good. The rest of the perimeter of the building could have the same problem but maybe it is blocked off enough that a failure there would not be such a risk to people. Allen has been ridiculed by the armchair quarterbacks but he was 100% right in warning the city. There are various ways to design basement walls to retain soil pressure and this project was not designed to resist soil pressure without help from the street level floor slab. That doesn't mean it's going to collapse immediately, people dig trenches all the time to repair pipes and get away with it, but occasionally you see on the TV news where one of those trenches collapsed and buried some people.

[@MajorCaliber]

@@billj5645 _... this project was not designed to resist soil pressure without help from the street level floor slab._ So that implies that it was temporarily shored during construction too--not unusual. Would LOVE to see a ton more construction photos, esp. the formworks and placement of the garage floor slab and retaining walls, and, of course, *the remediation of the CRANE COLLAPSE,* which nuked a lot of formworks, and possibly some placed-but-not-yet-cured concrete as well. Red flags everywhere.

[@MajorCaliber]

@@jeffostroff Even though there's probably sheet piles on that Collins side too--as plainly seen on the South side--who knows whats left of them after 40 years of soaking in the somewhat salty rain and groundwater of So-Fla? Better safe than embarrassed. ;')

[@gregj.gotham4402]

Another great video. More and more questions keep coming up on the design or as built. I’ve never seen so many design questions on a building. It’s very saddening between the design and the failures that took so many lives. Thank you for your continuing efforts to help find out what happened and why no slow failure but all at once. R.I.P. all the lost souls.

[@jeffostroff]

Awesome, thank you!

[@kevinverduci7600]

I really like your work and you seem level headed. I am a union carpenter Foreman and maybe you could humor me and hear my theory. I have done many jobs with" quick fixes" no permit and I hate that. Suppose the huge floor above the the ramp on the east side had visible crack from expansion or stress. Property management needs a quick fix they have a guy hammer drill a new beam and pour concrete to add strength . That would explain the water seepage because concrete was already on the floor . That would explain the water seepage the mysterious column and the rebar there? Is there any way to get a PDF of the blueprints somewhere so I could mess around looking at them? I'm not a pro but I've built a lot of buildings and you're brilliant tutorial has got me really interested in this

[@MajorCaliber]

IIRC, it was in the Fiorella video, south-central portion of garage, you could clearly see a large rectangular section of the on-grade slab had been sawn out and replaced, clearly different color, texture, and weathering/staining of newer portion of concrete... anyone ever spot the requests/permits for that fairly major job? ETA: yep, it's @3:54 in Fiorella's video, near spaces 50-52, and encompasses at least 3 columns plus overlap, so a "patch" that's at least 50 feet long East-to-West, and... done by the handyman?... by a licensed contractor?

[@jeffostroff]

It would be a lot easier to find that permit if we knew what year it was done period it is also possible that may have been done without a permit

[@MajorCaliber]

Edit2: although not as much color contrast post-collapse (due to weeks of rain, mud, and heavy equipment traffic), you can clearly see the NW corner of the "patch" in the video above starting @4:04 ... it takes up a good portion of lower-left frame... looks like it's completely OUTside the building, but very much *in the heart of the infamous PLANTER ZONE* ...

[@johnbergstrom2931]

Well, I'm sure when the info comes out about CTS's so-called 'maintenance', we are going to be gobsmacked. It wouldn't surprise me if the work had been done by people they loaded up from the sidewalk outside Home Depot. "Can you do waterproofing and structural concrete repair?" "Oh, si, si.."

[@MajorCaliber]

@@johnbergstrom2931 Yep, every ducat saved in the "yucky" garage was more to spend on the very shiny marble in the "fab" lobby, and the oh-so-pretty planters by the pool... smh...

[@stache1954]

@@johnbergstrom2931 So much of that going on.

[@markiefufu]

Your analysis, along with 1 other channel are the only 2 I trust. All these other KZbinrs obviously don't know what they're talking about. They'll confuse themselves as well as their audience as they are through. Keep up the great work!

[@jeffostroff]

I appreciate that Dazzlefoo!

[@surelyyoujokemeinfailure7531]

I'm trying not to remember the unhappy cats on steel cable leashes. Wtf.

[@seminolefantodd4736]

Yes about confused KZbinrs. One claimed the collapse started on a completely different column near the west at the portion of the building that didn't fall and claimed punch through of the pool deck brought down the east. I was saying, "wrong, wrong, wrong," through his whole presentation.

[@johnbergstrom2931]

@@seminolefantodd4736 Be honest, it was that Kai clown, right?

[@MostlyLoveOfMusic]

The guy from Building Integrity does a good job discussing this building

[@hellothere9938]

1. Column on top of middle of H beam is larger than others. 2. This Column carries weight through all floors except basement. 3. This Column is not exposed to water and is at full strength. 4. Garage level columns and floor have rusted rebar and concrete that has reduced strength from 40 year water intrusion per the engineer. 5. H beam falls without the first floor dropping, per residents that went to front desk+ images in video. 6. This column is hanging almost free with nothing under it except basement floor. The rest of the building then falls pushing the column into the basement floor like a battering ram with thousands of tons of force with no rebar below it to impead it's 10 foot drop( like the other basement columns) . 7. The cement dust and debris fill the gaps in puncture hole in the floor. 8. Someone sneaks in to inspect hole for loose concrete vs formed/whole concrete and checks rebar count matches specifications. 9. BTW.. column not the main or first cause of the collapse.

[@jeffostroff]

Yes I don't think the column or this beam was the root cause of the collapse either as if you look at the security video camera from the hotel next door you can see that the collapse started pretty much around left of center of the building which is more over where the planter area is in column M 11.1. However I don't believe that the floating column impaled into the garage floor because I think there would be a lot more damage to the floor like craters and cracks and stuff like that you can't just displace concrete like that mine is just thick it has to go somewhere and it usually would just pulverize into pieces

[@johnbergstrom2931]

#5 is wrong. That H beam falling would have dragged the whole east wing down with it. Would have instantly compromised 5 columns. #6 is wrong. Column K was really just a series of columns, poured at different times. It was also connected to the slabs at every level with rebar. It wasn't one long 'battering ram'. It would have disintegrated as the building fell. Also, even if it were one long, 120 foot column, the garage floor slab is 9 1/2 inches thick. A column free falling one story only achieves a velocity of about 15 mph. So an intact column K, which in total weighed less than 30,000 lbs, hitting the garage slab at 15 mph, WOULDN'T DO DICK. It would crack the slab and make a divot a couple inches deep, then just fall over to the ground. Also, "thousands of tons"? NO. The building in total weighed 10,000 tons. Several dozen columns supporting that weight. Maybe a load of a hundred tons being carried by column K. But once it started to disintegrate, that load was irrelevant. It wasn't transmitted straight down. #7 is wrong. Because 6 is wrong. So, thanks for playing, here's a nice parting gift, don't let the door hit you in the ass on the way out!

[@seandayton6557]

After reviewing the 1979 structural plans and reviewing the still image @ 4:17 of this video, I submit the following... Column K was not structurally tied to Beam BM35 with J-Hooks nor was it tied to the lobby slab with J-hooks. This is clear as no structural details for tying the 2 structural components together were provided in the 1979 structural drawings. It is also clear from the still image @ 4:17 of this video as there is no reinforcing steel protruding from the center of BM35 where Column K should have been structurally tied to BM35. I would tend to agree with prior comments that the "mystery" column is actually the lobby end of Column K which penetrated the garage slab during the collapse. Notice that all the other remaining columns have some concrete within and round the rebar and there appears to be none left within or around the rebar protruding from the garage slab at the "mystery column". Yes, one would expect more damage from the garage slab if hit by the full weight of an intact column K during the collapse. Based Morabito Consultants 40 year review and recommended repairs I don't think it would be a stretch to propose that column K at the lobby slab just above BM35 had also degraded due to water intrusion rusting the rebar and breaking the bond between the rebar and concrete allow for the easy penetration of the garage slab by rebar of column K. This condition alone should not have caused the collapse but if the the rest of the columns at the lobby slab level were experiencing degradation due to water intrusion as well then that could have very well lead to the collapse. Just my two cents from a couple decades in the industry...

[@jeffostroff]

We noticed the same thing, maybe 2 little rebars, but this column does not seem to be held in place very well.

[@johnbergstrom2931]

Well, it was probably at least tied into the slab, even though it doesn't show it on the drawings. It was a 'floating' column, but they didn't just let it float on the slab. Column K probably had 100,000+ lbs of load on it. If there was no rebar at it's base, it would have started cracking and failing 30 years ago... Not even an incompetent concrete worker would be that negligent.

[@fraidykat]

And I think you're spot on.

[@terrymoreland6446]

I'm presuming they got the whole slab dry during the initial pumping. At that time, if this is a matter column K impacting the slab and embedding the rebar, then there should be spalling and possibly cracking of the slab which would have been obvious when dry. Don't think structural engineers would miss something like that... Not to mention that area of the slab could be removed for forensic analysis.

[@fraidykat]

@@terrymoreland6446 That spot requenches itself every time the tide comes in. Pumping is futile.

[@EristiCat]

RE: The mystery column: Given the amount of rebar in the mystery column it seems VERY unlikely to me that it was built as shoring before the collapse. Here's why... If it was to be shoring it would be used almost exclusively as compressive material to hold up what? Would it have been placed UNDER the existing beam or UNDER the first floor slab. If it's supposed to hold up that H beam how is it going to do that with no foundation other than what is probably a 6 inch un- or poorly- reinforced slab? Were that it's use there should be evidence of the slab being cut so a real foundation could be put there for this column. No foundation means you don't expect it to hold up much but if all you wanted to hold up with the first floor slab for a few months it might suffice... But if you are just putting in a compression supplying column why would you stuff that column with all that rebar? Makes no sense. Rebar is to resist tension load and moments, as a shoring there isn't going to be much/any tension or moment load for this temporary use. Also keep in mind that shoring that is not under load isn't shoring anything. You can't just place something under something else to shore it up, you have to move the upper stuff UP while you are building the shoring, make the shoring "too tall" and then let the "stuff" back down on top of the shoring so that the shoring will start providing some of the resisting force. If you don't you get no shoring effect until such time as the stuff over it has sunk/settled down on top of it. That's certainly OK if that's your plan, sort of a we want this here in case it settles more. But that also works against putting lots of steel reinforcement in the concrete.. shoring that's not even touching but is just hanging around "in case" needs little more than compressive strength, not a bunch of moment resisting steel. There is no evidence that H beam was weak and needed shoring, to the contrary it was so strong it held together throughout the collapse and remained intact. If the problem was the columns holding up the H beam why would you put your "fix" in the middle of the drive way? You'd put it at the H beam ends to strengthen the columns holding up the H beam. And I would suggest that as a temporary measure you would use steel, not concrete.. more next... Next.. and perhaps more importantly from a logical construction standpoint... If I felt the need to get something into place here as temporary shoring I would simply order a 12 foot (whatever the distance was from slab to point of top of shoring) section of steel I-beam (to use as a column) along with 1 or 2 inch thick steep plates to use as bearing surfaces at the top and bottom. Once fabricated you could get them in and done in a day. Weld the I beam column to the plates. If you wanted to get fancy you could bring in some large building jacks to spread the plates an 1/8 inch so there would be some preload on the I beam column after welding things and pulling the jacks out. You could place this steel where the "mystery" column is or you could put it next to the columns holding up the H beam. So what we are left with IMHO is that the mystery column is not some temporary shoring. Even if it was thought a temporary support was needed it would make far more sense and be much easier to construct out of steel then to form and pour a concrete column inside the parking structure. The mystery column is what it appears to be, even if why don't know the sequence of failure that put it there, it's some portion of the column that originally was on top of the H beam.. sheared off and speared into the slab. ***What we are seeing might not even be the lowest segment of the sequence of columns that rose from the H beam up to the penthouse. The segment that originally sat on top of the H beam may have buckled and slide off and been removed by NIST and the part we are seeing speared into the slab may have been from the 2nd or 3rd floor. Who knows, we're all just speculating.

[@zedgravitus1836]

The column starting on the H-beam shifted and the column from the first floor impaled the pad. I bet the investigators confirm this by accounting for the entire length of that column, minus what impaled the floor of the garage.

[@jeffostroff]

no, angle is not right, and there is no damage on the concrete floor from being impaled.

[@whirlwind8825]

You are correct . The beam was pulled south you can see the steel is all bent that way and the column came down and punched the slab ..Mystery solved

[@johnbergstrom2931]

@@whirlwind8825 Don't ever become a detective.

[@whirlwind8825]

@@johnbergstrom2931 Stalking me from another comment only shows the sociopathic person that you are.

[@whirlwind8825]

@@johnbergstrom2931 John I do not blame you for being a sociopath. Its not your fault. I blame your parents for raising you to grow up to be this way . I blame them. Not you .

[@clarkjanes3094]

Since the basement floor at the mystery column looks very even instead of showing signs of impact, my guess is it was a retrofit column put in after the video. Maybe they drilled holes into the floor to install the rebar then built up a column to the ceiling. Because it was a retro fit, the new column's concrete would break away from the original floor surface rather cleanly. Would need to see the underside of the crossbeam to check for an attachment point.

[@jeffostroff]

Bingo! That has been my theory also. And I suspect without permit

[@johnbergstrom2931]

@@jeffostroff Jeff, go to the Morabito plan for repair and restoration. It's on the Surfside site "Preliminary review plans for 40 year recertification", uploaded July 3, 12:46 pm. (Near the bottom of the page). On sheet S2C-2.9, top left corner is a drawing of a grade beam tied into a "New column". They always intended to add columns for support. Not really sure what they were supporting... In the video, there is no excavation for the grade beam, so we swing back to illegal, unpermitted construction by people who didn't know what they were doing. Also, I'm not sure if the Morabito work had even started yet...

[@andrewostrelczuk406]

Just discovered your channel, and I’m gonna say I’m impressed! So I’m going to Identify as an Arm Chair engineer, 20 years of Army Service, seen some amazing Sheet in my life. I know that you have mentioned that the Mystery Column was not saposed to be into the basement, my idea is that the possible way that a column should have been connected with the H-beam is/Was a Pocket that it would have set in. Like a upside down dragons tooth. A little bit like a pyramid with the top cut off. It was at the bottom of the 12 floors above it and IMO, it would have significant pressure to the side loading to the East with your description. As well as the down pressure from the weight of the building above. Hey I’m not a school trained engineer just got this as an idea. And I’ve seen nothing on the build structure of the H-beam. But in the pictures that you have shown with the water filled in around the mystery column it would have been a fantastic failure to the outside of the East abutment (might be the wrong word to describe it) where the tooth was lodged into the “H” and if it’s the beginning end of the column then it could have a lot of re-bar starting there and then at the Flange it would flare to widen to (did you say 14”) in that case the rebar guessing it to be 10-12 inches deeper in the tooth and that the flange was the point at which it stopped in the floor of the garage. Subsequent removal procedures would have stopped at the end of the flange and making it seem more like a column was there. The only thing that I do not have a scale to measure the amount depth, and inclusion of the leaves of water indicating that it is a low spot in the garage floor IMO support the impact into the floor and cracking should also radiate from the surface of garage floor. Hey I’m just going to leave it at that. Maybe I got it right, maybe I’m totally off it’s purely speculation... on my part.

[@awidesigns]

Its a trick of the eye, that rebar is not coming out of the slab rather laying over, ie, its the rebar from the penthouse column that sits on the H beam. If you look at earlier pictures its off the ground not touching the concrete and still connected to the H beam.

[@jeffostroff]

show us links to these earlier pictures. If it was loose NIST would have taken it like they did everything else

[@wadeturner2665]

The column that starts on the first floor and sits on the cross beam of the H, would that have been rooted into the H beam? Or just into the floor itself, just above the beam? That column was actually rectangular in cross section. The re-bar protruding from the floor appears to have a square footprint. Really looks like that the column in the basement floor was an addition, not an impaction from above.

[@jeffostroff]

Good question Wade, I think rebar should have been placed in the H-Beam straight up where the column goes, then the floor slab is poured, and the rebar continues up through the floor to form the column.

[@wadeturner2665]

@@jeffostroff That's interesting, because when I look at all of the pictures and video of the H beam you included in your video, I don't see any evidence of rebar protruding from the top of the cross beam. It would be interesting to get someone to sneak onto the site and get some close up pics of the floor and the mystery beam. If a new column was added and set into the floor then there would saw cuts into the slab. However, if that had happened, and this created a path for water to flow upward onto the top of the slab, that water flow would likely have been happening before the collapse. If there was a mystery column in place before the collapse it looks like it would have interfered with driving and parking. It shouldn't be hard to find a survivor of the non-collapsed section or other recent visitor to the parking garage to confirm that.

[@johnbergstrom2931]

Good eye on the column squareness. Yes, column K (the one supported by the H beam) was 12" x 24" and that proto-column is certainly bigger than 12" in either direction. The H beam, 1st floor slab and column K were theoretically all tied together with rebar, the column was just not plunked down on the slab where it could 'slip off', as suggested by the 'impalement' crowd. The configuration of the rebar depended how they poured the elements, chronologically. It might be that that they formed the H beam without any rebar tied to the slab, waited for it to cure, then poured the slab above with a rebar connection to column K, but not the H beam. Since they don't really have earthquakes in Florida they were not expecting any lateral forces, this was an acceptable way to do it. Maybe that's part of the answer. If column K was only tied into the slab, not the H beam, when the slab under unit 112 started to crack/sag (probably from creeping water damage and spalling) column K started to crack walls and shift out of plumb, albeit slightly. Panic ensued, and management told [somebody] to quickly add another column. "Don't bother with design or permits, get it done!"

[@designstudio8013]

It would be tied into each end.

[@designstudio8013]

@@wadeturner2665 there was 20' - the column

[@ajtony1313]

Re: The mystery column. I also agree that the mystery column does not in any way look like the result of a column piercing the garage floor. Looking back at the structural diagrams you show, in every diagram the column that sits on the center of the H-beam and extends up to the penthouse is always drawn smaller and rectangular unlike other columns in the area. However, the photos of the mystery column rebars protruding out of the garage floor appear to be from a relatively larger column. This input does not solve the mystery, but may point away from the piercing theory. Also, there appears to be a large number of rebars in the mystery column. Hard to count; 13 or 14? Would the number of rebars help determine the size of the column? As always. I am impressed with all your Champlain Towers videos.

[@jeffostroff]

This is a tough one to call. I want t be right there on the slab touching it and counting the rebar

[@ddhVapor]

You seem to be ignoring some factors here, first of all the column that sits on top of the H-beam might be smaller but it extended all the way up to the penthouse, so when it lost the support from beneath all that length, it had to go somwhere in a freefalling motion wich was uninterrupted for a height of the garage. It can be assumed with high possibility that the column shattered on inpact resulting the upper part of the column landing right next to it and producing the same piercing effect as the very bottom of it, the chance of this gets higher if that part of the building would fall vertically or almost vertically. If you look at the footprint of the mistery column you will see that it is highly irregular, for me it makes perfect sense that all the rebar we see is from different sections of that same long column landing right next to oneanother.

[@ajtony1313]

@@ddhVapor Thanks for your reply to my comment. Replies as such always make me reassess my original observation. Again, what perplexed me was the concrete floor surrounding the Mystery column appears to be too smooth to account for an impact of the 1st floor to penthouse column. However, your comment made me readdress the other factors. If you look at the architectural drawings of the H-beam’s four support columns, they appear to be slightly larger than the 1st floor to penthouse column that the H-beam supports. However, the rebars of the Mystery column have a definitely larger imprint than the 1st floor to penthouse column. This would fit your theory that the Mystery column rebars represent at least two sections of the 1st floor to penthouse column impacting the basement floor. Next observation, there is a clear picture of column N9.1/10 which is one of the four H-beam supports, and it clearly has 7 rebars. However, the Mystery column has either 13 or 14 rebars (hard to count), much too large a footprint. Great comment, I believe you are right. The mystery of the smooth flooring will have to remain a mystery, possibly the standing water is covering up some of the impact damage.

[@ddhVapor]

@@ajtony1313 I dont really understand what is the problem with the smooth concrete, it is smooth almost everywhere at the garage level. It is smooth even at the parts of the building wich was demolished using explosives, and at places it took the weight of the whole building ad remain smooth. Can you please share with us how it supposed to look like in your opinion? As for the rebars and the footprint: I cant know for sure but i assume that the column (starting at the 1st floor all the way up to the penthouse) wasnt a monolith as it was not poured all in one (unlikely if you ask me) could easily separated when the bottomofit hit the ground. At this moment the top of it was still pushed down by the partially collapsed building (as the eastern part collapsed last and slower than the rest) pushing it further down. If we assume that it separated at ceiling level (most likely) the bottomof the upper part could easily landed next to the already piled part (even as close if they were touching). if you account that amount of rebar (13-14) being 2 part of the same column right next to each other, paralel to each other it suddenly makes sense why there is somuch of it. This would also explain the dimensions of the footprint (both the size and irregurality)

[@ajtony1313]

@@ddhVapor First of all, I agree with your solution that the Mystery column was formed by two sections of the 1st floor to penthouse column separating and then smashing into the garage floor. You asked what I expected to see. The photos show that the column apparently penetrated the floor. I would expect to see shattered concrete flooring surrounding the point of ballistic impact of the Mystery column. As a projectile hits a concrete floor, first there should be cracking of the surface, followed by spalling (crater formation) and finally penetration. What I don’t see is the crater spalling. As I said before, it is possible that the standing water is covering up the floor damage/spalling that I would expect to see. Thanks again for a good solution to the Mystery column.

[@AyeCarumba221]

Seems like they could analyze that mystery column and determine if it has a footing. I'm thinking that it would not be super hard to determine if it was an original column, or if it was pile driven into the ground during the collapse.

[@johnminogue8055]

Jeff, unless I am mistaken if you look at the blue prints for the basement, there are columns that are about 2 ft or so away from the H beam on the left side. The H beam also looks like it may have been moved.

[@jeffostroff]

The H beam shifted over slightly as it dropped

[@kasuha]

I don't see any rebar coming out from the top of the center of the H beam so the beam sitting on top of it was not quite attached to it and after the H beam fell and slipped to the side, the falling column definitely could have had enough force and inertia to impale itself into the floor of the garage and start pretending it was always there.

[@jeffostroff]

Good point!

[@vipertwenty249]

Looks like that 5th column has stepped off the H beam during the collapse and punched through the concrete floor of the garage level - makes me wonder - was that floor undermined by water leaching out the ground below it? A test bore through the floor at that point may reveal it if so. Ultimately, could water be the cause of the weakening that led to the collapse? Edit: Reading through other people's comments after posting mine, it seems we're all thinking along the same lines - ignoring any other less than ideal design features of the building, water undermining critical supports seems a likely culprit given the rapid flooding of the site whenever pumping is interrupted. Was sufficient up to date and accurate information on the local underlying hydrodynamics available to the designers? Did any subsequent works nearby change that situation? Did the intrusion of the structure itself result in changes to the underlaying water flow that could not be foreseen due to insufficient data? It is in the nature of the ground to be opaque, and it is in the nature of man to err. Perhaps we are too reluctant to insist on demolishing inadequate buildings in the light of better new understanding.

[@jeffostroff]

Viper they are looking into all of this

[@fraidykat]

That is the single most logical place for where it came from. And you cannot see the full extent of damage due to the pooling water.

[@michaelmothershed3852]

I would be as interested to see how the column was supported . There should be a footing plan (assuming drill piers or piles , not pads ) If the foundation does not exist on the original plans , then it would likely be a repair addition . The column appears to be substantial with 4 bars each side (12 vertical column) should be a column schedule and a corresponding footing schedule that will list the column.

[@jeffostroff]

If this columns was added in the last 12 months, there would be no footer beneath it, all the piles were buried in 1980.

[@sparksrc]

Is there any markings of a beam on the bottom of the H beam?

[@jaslll4396]

The extra column is an upper floor column which punch thru the garage floor. The floor had water and dirt which filled in the hole in a way that makes it not look like a punch thru hole

[@jeffostroff]

We don't know you would get a clean punch through hole.

[@keithpeacock9282]

Maybe it's a punch down column, it was on top of the "H" beam but came off it when the beam moved and with the weight of building on top it punched into the floor slab.

[@jeffostroff]

Keith that is one of the ideas that I briefly considered early on but I think there would have been a lot more damage to the garage floor if this was some talk type of a punch through from above

[@winonakent]

@@jeffostroff But what if the concrete floor was so saturated with water by the time of the collapse that it was "soft" and not the very hard concrete that we're assuming was there? If the floor was soft, is it possible that the column from above was jolted off its base with the collapse and its rebar just cleanly punched down into the concrete without a lot of additional cracking and damage?

[@jeffostroff]

@@winonakent That does sound like a remote possibility Although from fiorella's video we could see that the garage was mostly dry so it's not like that area was saturated with water to begin with. I still think the more likely occurrence is that a is that a column was built there and even if it was built there it makes no sense because there is no pile under it to support it. Remember every one of those columns that comes up from the garage floor has a pile with a cap underneath it that goes all the way down to the bedrock limestone.

[@winonakent]

@@jeffostroff Perhaps there had been water incursion underneath the parking slab around that location for some time but not necessarily making itself visible on the surface? I still favour the theory that it's the remnants of the column above that shot down and impaled the concrete. Possibly it might not even be the bottom of that column. It might be a part of the column from farther up - maybe even midway up the building, or higher- which got severed during the collapse, and therefore it could fall from farther up and have more of a trajectory than if it fell from the 1st floor?

[@toweri_li]

@@jeffostroff You counter the most obvious answer (the upper column punched through the basement floor) by saying it must have been a new column built there - but immediately counter that by saying it makes no sense because there is no pile under it to support it. Additionally, there is not a shred of tangible proof to support that hypothesis. Just speculation. So what is actually your hypothesis? The upper floor column will have been pushed downwards when the building started to move. It is completely feasible that the building did not come 100% straight down, but pushed slightly to the side by the remaining columns. After all, the entire collapse sequence started by the pool deck collapsing, pulling the ground-level slab sideways, causing the columns supporting the building to tilt sideways, resulting in their collapse, taking the entire building down. The upper floor column may well have been punched throught the floor, filling any cracks and gaps left by spalling with very tightly packed concrete debris and dust. The concrete of that column must have been fragmented to dust, leaving only the abnormally thick rebars beeing hammered down by the weight of the falling building - ans eventually leaving them sticking out from the floor. As seen on the photos, the water will have leveled the surface nice and even. Without actually hammering the areas in between the rebars, one may not even notice that the tightly compressed material surrounding them is not actually solid.

[@imconsequetau5275]

OBVIOUSLY, the H beam did not drop straight down, but the four supporting columns hinged sideways during collapse. It is now straddling the neighboring column patterns.

[@imconsequetau5275]

The four supporting columns hinged northwards as a parallelogram.

[@jeffostroff]

I slid down the 4 columns and landed about 12" north of them

[@chaseman113]

Wow, what a twist. More goofy unofficial stuff related to the penthouse and rule breaking/skirting in construction. Enjoying the vids/format dude.

[@jeffostroff]

Thanks, I'm glad you liked it!

[@Onoma314]

You should do a video on the mass damping system used in the World Trade center towers. It was the very first high rise project in the world to use a new type of Viscoelastic damping from 3M

[@jeffostroff]

Yes that was an incredible design, seen it in the documentaries

[@MajorCaliber]

To support the "Recently Added Shoring Column" thesis, I would add that there are several retro-fit piling technologies that could support a retrofitted column. Some could be deployed with the limited ceiling height in the CTS garage... but get out the checkbook.

[@jonathaneastwood2927]

Cheque book.

[@jeffostroff]

Or they could just drill hole for a few rebars and pour a column real quick knowing it might be a temporary fix

[@johnbergstrom2931]

@@jonathaneastwood2927 Oh, you mean credit card...

[@johnbergstrom2931]

Well I've scoured Surfside's public records looking for a CTS permit for an additional column and NADA. If they didn't do the work above board I doubt they sprung for a new piling. It might be they just haven't digitized it yet but documentation of structural work on a building that collapsed would have priority...

[@MajorCaliber]

@@jeffostroff Still need some kind of jacking mechanism to get the new "illegal" column to actually take up some load from the failing slab overhead. Just casting a column floor-to-ceiling (using Mafia-Mix, nach) does almost nothing... except add to the floor's dead load, lol.

[@ruperterskin2117]

Right on. Thanks for sharing.

[@crazyirishmanartist]

Wonderful informative video. If I may make a suggestion, if you could adjust the mouse cursor to be a little larger and of a color other than white, it sure would make it a lot easier to follow your narration. Looking forward to your next video!

[@chickenray182]

That mystery column has beefy rebar.

[@jeffostroff]

Yes, all the columns have large diameter rebars, which is why they can accommodate usually only 4 for them across the column.

[@MajorCaliber]

Yep, and maybe they were even going to put thee only drop panel/capital in the whole tower atop that one column for better punching shear resistance... but talk about denial... can't quite call it *whistling past the graveyard* as there's so little precedence for this happening to a building this age in N. America, but "lawdy lawdy"... seems like some expensive X-ray, ultrasound, etc. equipment should've been deployed long before the recent re-roof job was started.

[@MajorCaliber]

_At a Miami Beach lounge, 1979, 2AM, 3 sheets to the wind_ ... William Friedman, Architect: "Hey Sergio [Breiterman, Engineer], think we oughta beef up these 4 columns under the H-beam, from 16-square to 24-square?" [Punching buttons on his TI-55 calculator...] "Naw Bill, [hiccup] too expensive, that's why I spread it over 4 columns to begin with... she'll be fine... I do it that way ALL the time... all up and down this coast... " =:O

[@jeffostroff]

That would not surprise me at all!

[@johnbergstrom2931]

I agree, all the columns in the garage level should have been 24" x 24". But you're forgetting, the tiny pool deck columns are the ones that ultimately brought down the building through punching shear. Even on 16" x 16" columns, the 24 inch wide 'lintels' atop those columns, formed by the H beam legs, there's no way in hell the slab would punch through there. With the position of the mystery column, it could have only supported the slab above. Then again, who knows what their intentions were??

[@horsewithnoname12345]

The mystery beam looks very different from the older, original beams. The concrete, the rebar, the fact it wasn’t necessarily attached to the original structure leads me to believe this was a recent addition. Part of the initial repairs.

[@hg60justice]

there is no apparent concrete around the re-bar, but it's not a high enough resolution to be sure. it could be the column above came down with such force it drove the rebar into the floor. enough to leave the re-bar behind while the concrete exploded away. it would have left the slight impression as it spalled away too.

[@jeffostroff]

but where is the floor damage from such an impact?

[@hg60justice]

@@jeffostroff you can see a slight square outline . but it is too low a resolution to get it bigger. there was nothing there before the building fell, unless the H beam is somehow shifted to a different set of columns in appearance. i think it's sitting close to in place. close up at 13:47 doesn't show anywhere the column was tied to the H beam either. i've done a bit of concrete when young. on a placing crew pouring large projects. that's some beefy rebar in the floor the only similar close re-bar, is center left, but i don't think the column was sitting over there. concrete was probably already missing around a few inches or foot or so from coming off the H beam. as it hit and drove in, it started buckling, causing the rest of the concrete to spall away. at the floor it has a slight inward slant towards the H beam. there is no magic, so we have to come up with a reasonable explanation. 😀 not many other explanations,. not that mine is an exact explanation either, just a logical probability.

[@hg60justice]

@@jeffostroff guess it's like low/high velocity fasteners. they quite often sink with little to no spalling either. might be a better analogy. they did drop 1 story before striking. with whatever force was the weight supported by that column. as to floor damage, it looks like little damage overall to a floor that had a building drop on it. the lower floor does look mostly intact everywhere.

[@MajorCaliber]

HMOG!.. @7:05 are those post-construction, NOT-in-the plans, large (3"?) diameter *plumbing penetrations* made in the weakest part of the H-beam, i.e. *right under* the unseen column it was made to transfer the load of? PLEASE tell me I'm seeing... not that. IIRC, such penetrations--if made at all--should be in the MIDDLE part of the "web", away from both max compression (top) and max tension (bottom)... lawdy. More to the point, WHY not put such holes WAY closer to a column, instead of RIGHT where all the "action" (load) is??? =:O

[@jeffostroff]

Yes indeed and it is doubtful whether that was done by a licensed plumber, even though the use of mission connectors is certainly allowed and they are somewhat reliable, I would prefer to have it completely cemented PVC pipe if that is indeed what they used, or perfectly threaded metal pipes if that is what they used there. It's hard to tell because it could be either painted white iron pipes, or just white PVC pipes. But either way yes looks like handyman work non engineering

[@johnbergstrom2931]

Wow, I hadn't really noticed... From what I can tell, they missed all the important rebar (it's put 1.5" from the top and bottom of the beam) but they may have drilled through a couple of stirrups. I sure wouldn't have wanted to be the one assigned to drill that hole - 24 inches of inhaling dust!

[@johnbergstrom2931]

The plumber probably didn't know what the beam was, that it was supporting ~100,000 lbs of building, before he fired up his drill...

[@MajorCaliber]

Was hoping I was wrong... the deadly game of "Reiber's Jenga" continues... a few afterthought cores drilled willy-nilly over here for plumbing/electrical services, another few over there for materials testing... cast-in-place "beams" with only 2 top rebars and 2 bottom rebars... the "Swiss Cheese" failure model gains ever more data points... this proverbial camel very much needed a back-brace.

[@johnbergstrom2931]

Know what I just noticed after watching the video again? There are no penetrations in the wrecked beam... And if you look at the garage walk-thru video again, you see the pipe does not go through the center section, it runs along the beam but goes through the slab near the K column. Since the K column borders the kitchen units, it is logical to assume it's serving as a drain stack for those corner kitchens.

[@Jeswald1]

Another brilliant video! The first thing that (strangely) came to mind was a scene from the movie “What’s Eating Gilbert Grape.” Gilbert (Johnny Depp) and his friend are secretly shoring up the floor under his mother’s sofa; she has gained so much weight that the floor was in danger of collapse. Knowing his mother would be furious if faced with reality, Gilbert attempts a quick and secret fix by adding a column directly under her.The cement around the mystery column looks very fresh. If an engineer pointed out that the support in that area needed immediate attention, I’m sure that would not have been made public, because the tenants would be inclined to sell. Looks like a quick and dirty job to prepare for certification.

[@jeffostroff]

Yes, every piece of evidence opens up new questions

[@joecrowe7062]

That's a great scene,brilliant

[@erika8627]

At 6:58, there is another red column. 87 or 67 I believe? There must be a reason why those two particular columns were painted red and not yellow. They also both have some type of wiring coming down to a box. Is it something fire dept. related maybe? A fire alarm pull perhaps?

[@jeffostroff]

That could be, there are no extinguishers on them

[@kevinpepe9101]

My personal untrained belief is the mystery column is impaled into the garage floor. That column appears to be carrying a significant amount of weight of the building. I wouldn't think it that difficult for it to impale itself through the concrete floor of the garage. Might also explain the water in the area as well. Just a thought.

[@jeffostroff]

Yes I don't think it was impaled, I think it was added in the last 12 months before the collapse

[@jeremyh9338]

my guess is ...look at the picture at 13:59 in the video---in the upper right corner (on the image the H beam) that has red paint on it was supported by the column behind it in the image (re-bar that is painted blue ) the "mystery" column was the support for the end of the H beam that is closest to you in the image ( end of H beam that has tan foam like material sitting on the H beam) If you took just the H beam and slide it up and to the right in the image it would line up with the mystery column and the column painted blue. The H beam most likely did not fall straight down. if the pool deck failed first it would have pulled the H beam towards the first columns that failed. similar to how the failure of the pool deck pulled the support columns that held up the side of the building facing the pool deck.

[@designstudio8013]

good analysis. The mystery column - 01-8 had a L type pilecap. The view on the video is wrong.

[@SurgeDashcam]

I see where you're coming from, but that blue column is in the basement floor plan ALONG WITH the red painted column supporting the upper right (from your view on the timestamp). That and looking at the position of the other columns suggests the H-Beam is in its correct place in relation to the drawings.

[@jerryclark4628]

The column started in top of the H-beam - when the H-beam fell it moved slightly north allowing the column that was sitting on it to fall vertically and punch through the basement floor - I bet the rest of the column is there below the steel sticking out of it. There is likely a void under the floor there allowing the falling column to punch through easily. Look at the earlier picture -the steel is sticking out of a hole - in the later picture the hole has been filled with mortar - seemingly a deliberate act to hide that the column actually punched through the basement floor.

[@jeffostroff]

believe it or not, there is no evidence on top of the beam that there was a column there!

[@NutmegThumper]

Would need input from residents to see if a new support column was added. Based on the general condition of the garage, I’m doubting it. Was there perhaps rebar under the basement slab that was forced upward through the floor?

[@johnbergstrom2931]

Watch the video again (full screen) at 13:47. You can see a clear, rectangular outline where the slab was cut and patched after the rebar was installed.

[@scotttoborg4906]

It's the 1st floor to penthouse column supported by the H-beam. It appears to have sheared off the H-beam and was driven into the garage slab by the weight of the building collapsing and the inertia of falling 8+ feet to the slab. The distance from the H-beam indicates it sheared off before the the H-beam fell.

[@jeffostroff]

you forget that there is zero damage on the floor where there should have been craters or something else if it had impaled into the floor but there is no damage. These rebar rods look like they were intentionally built up out of that concrete floor like it was done by somebody in the last 12 months, since Fiorella shot her video inside the garage in July 2020, showing no column exists where that mystery column is.

[@Lawleygagger]

@@jeffostroff what about all the columns in the basement that still have concrete in them,except for that one.I to believe it came from above

[@johnbergstrom2931]

Boy, that is bizarre. If it was an addition, attempting to shore up the transfer beam, it had to have been added between July 2020 and June 2021. It was unauthorized work and ultimately pointless, as there was no piling beneath that spot. I guess they could have cut the slab and added a regular-type footing, but I'm not sure that would have been effective on sandy soil, especially soil saturated with salty groundwater... Maybe now we know why they haven't removed that H-beam from the site. They're trying to figure out what the hell that column was! The mystery deepens!! Edit: Even the 'shoring up' theory is suspect. That mystery column is inline with the 'O' columns, not right underneath the 'floating' column K supported by the H-beam. K is offset from the 'O' row by several feet to the west. It wouldn't have done anything to carry the loads.

[@jeffostroff]

Yes this is got me stumped

[@johnbergstrom2931]

@@jeffostroff And by the amount of rebar they used, I wonder what the hell they thought they were supporting...

[@KayInMaine]

I think you're right John.....the beam was added recently....sometime in the last year after that real estate woman took video of that area! Has to be why it's there. That's proof that there was weakening going on in that area and they were putting a bandaid on it.

[@kmagnussen1052]

@@johnbergstrom2931 it would have provided little support to the building as a whole. The H beam stayed intact that beam did not fail so it was dong its job. Most everywhere else the columns small that they were went all the way to the top floor, there may be a few exceptions . The H beam transferred the load of one column to four columns.

[@johnbergstrom2931]

@@kmagnussen1052 Thanks for parroting information I'm already very familiar with... Nothing original added.

[@jonathansherwood5841]

Hmmm, does the concrete around it appear to be cut? Hard to tell from the pictures, but maybe it was added as an afterthought? For shoring up, like you said. Is it even possible for vehicles to drive around that column? When was her video taken? If it was added in, seems like it would have to be after her video was recorded. I agree with you, impalement seem highly unlikely.

[@johnbergstrom2931]

The vehicles could have inched their way around a column at that location, but it would have effectively made 2 parking spaces, 17 & 24 unusable. Impalement was my first thought, too, but it wouldn't be that clean. The slab would be all broken at that location. Edit: The mystery column wouldn't have blocked spaces 17 & 24, or any space directly, but it would have made using spaces 18-23 (to the east) much more difficult.

[@jeffostroff]

Fiorella's video was shot in July of 2020. So if somebody added this column, it happened sometime in the 11 months leading up to the collapse

[@johnbergstrom2931]

At 13:47 you can see a regular rectangular border around the mystery column where somebody patched the slab.

[@bob-who-must-not-be-named8522]

@@jeffostroff perhaps someone can ask a resident if any new columns had been added in the garage. If that was not punched in, then the only other explanation is that it had been very recently added, indicating someone was very concerned about that H-Beam, and yet there seems to be no documentation about it.

[@rubyoro0]

@@bob-who-must-not-be-named8522 That’s what I don’t get…why are residents not stalking these videos like we are?

[@mjohnson9563]

Not an engineer but I work in accounting and I get involved with transparency and oversight and here is my guess on that mystery "column" next to the H Beam. Once the debris had been cleared from the garage floor NIST wanted to do a groundwater leakage test to see how much ground water could seep into the garage. They cut our a rectangular spot next to the H Beam as the H Beam is putting a lot of stress weight in that area of the garage floor and would enhance any leakage. Then they took one of the damaged columns from another section of the collapsed building and sunk it into the ground where they cut our the rectangular section of the garage floor and leveled it out with some new concrete. No, the column being supported by the H beam did not impale the garage floor because it was tied into the H Beam itself and when the H Beam fell and shifted minutely, the column supported by the H Beam would have crumbled due to lateral shifting. Also, where are the blue prints for the 13th floor penthouse apartments? Finally, the structural engineer who designed this building, what other buildings did he design and are those designs being reinspected just to make sure that any building inspection dept. would not have missed something by chance. Thanks again Jeff.

[@jeffostroff]

It is highly doubtful NIST would do anything destructive to a column like that. They carted everything untouched to an off site storage area

[@johnbergstrom2931]

Yeah, no... If you want to measure groundwater infiltration, you simply drill a hole, hook up a hose and just measure how much water you have to pump off to keep it dry. You'd have to do that in multiple locations to get an accurate picture. I don't think NIST was really concerned with groundwater, except keeping the slab dry so they could work... The pool deck collapse brought the building down.

[@designstudio8013]

nope

[@safe4jam]

It has clearly moved over and is no longer blocking the driveway. At 14:40 if you line up the the two columns in the foreground toward the ramp you can see how far back the beam is sitting.

[@jeffostroff]

You are wrong. You incorrectly identified the two columns those are not the columns that the H beam was resting on. The four columns of the H Beam was resting on are still there right next to the H beam and still touching it so it only fell 12 inches to the north. And by the way the each beam is still in line with the bottom of the ramp. If you take a look at the overhead photo as i showed earlier in the video comma you will see it fell directly where i said it fell which is still in line with the bottom of the ramp.

[@sandblind]

It sure looks like the mystery column is the vertical column from floor #1, which slipped off the H beam during the collapse and punched down thru the slab. What is truly odd to me is that there is no rebar protruding from the H beam vertically into the 14 story vertical column. It appears the vertical column was just floating on top of the H beam - is that normal construction? Possibly, because the H beam might "flex" by small amounts... idk?

[@jeffostroff]

Yes the column on the first floor went all the way up to the penthouse and it was a floating K column 12 inches by 24 inches. And they have it resting on that middle beam of the H beam bit of the garage floor where it would block the driving lanes. So the age beam rests on top of four columns which then take the load from that one column and re distribute it to the outside lanes of the traveling in the garage. But I doubt that the column came down in Pierce to the floor because otherwise there would be a lot of damage to the floor

[@tchevrier]

that mystery column looks pretty large based on the amount of rebar sticking out of the floor. Far more rebar than the other columns.

[@jeffostroff]

Yes like a handyman special made in the last 12 months

[@metatechnologist]

@@jeffostroff Somebody saw something and tried to fix it?? That would be in HOA records.

[@manikaggarwal2018]

@@jeffostroff it’s not a 12 month old job

[@johanterblans8266]

That column is even visible on Google Earth of the roof. It super imposes perfectly

[@Cert_if_eyed-Muff_dye_vEr]

The rebar from the mystery pier is anchored into a pier below grade. It didn’t come from above because the rebar above would have to tie into the anchored rebar. That’s what iron workers are responsible for and it’s inspected before the concrete can even be poured. And before they can start a new level the rebar has to tie into the lower level. That mystery column is in the video of the garage. The beam starts at pier 15 and then 3 other piers at the opposite end of the beam. I can’t make out the numbers but it’s there

[@jeffostroff]

No it is not there. I need to make another video showing where the beam is in the garage

[@TechItOut]

_"When you have eliminated the impossible, whatever remains, however improbable, must be the truth. "_ It is a tangle of broken bar just sitting on top of the concrete floor?

[@jeffostroff]

Some have proposed this, but it sure looks like it is coming out of the floor, not sitting on top.

[@johnbergstrom2931]

God, I love all these truly dumb people quoting Sherlock Holmes. Jesus.

[@billj5645]

@@jeffostroff It does look like that, and not so much just some debris laying there. Also it has been there awhile without being visibly disturbed by other activities.

[@manikaggarwal2018]

You are correct

[@boataxe4605]

San Francisco is soon going to have a “Hold my beer” moment.

[@johnbergstrom2931]

Oh, from that high rise that's tilting into the ground?

[@boataxe4605]

@@johnbergstrom2931 Yep.

[@johnbergstrom2931]

@@boataxe4605 How bad is it getting?

[@boataxe4605]

@@johnbergstrom2931 Off plumb by 12 inches and still sinking. The property owner and city inspectors have agreed on a fix that just about all outside engineers say won’t work and may make it worse.

[@MajorCaliber]

@@boataxe4605 I know that only in times of REAL (national survival) WAR can we do things with UNlimited budgets, BUT... given the $$$/sq. ft. they planned to (and did) get for this prime real estate, they may have "saved" just a wee fawkin bit too much on that lame foundation... then I remember it's in one of thee most infamous *seismic zones* on the planet, and I'm thinking JAIL TIME _after_ several PE licenses are pulled... lawdy, it's not like that tower set any records for height. Bedrock was available, but they went for friction. Would love to see some city.gov and insurance company emails subpoenaed... will she collapse before she tips? =:O

[@thekekronomicon590]

Something I noticed is that all the other pilings have some concrete left near the bottom where the rebar goes into the ground but the mystery column does not which probably means it was built differently than the rest of the columns.

[@jeffostroff]

While you are right that most of the columns do have some sort of concrete at the bottom if you look closely on other photographs of the completely empty site, you will see that some sites there are missing columns, and in some other areas there might be just a few rebar's coming out that have no concrete in them and yet they are still coming out of the floor. So I don't think the lack of concrete tells us whether there is a column there or not because at this point we have no idea what stuff the excavators took out of there and cleaned up

[@ravenbarsrepairs5594]

In the garage video, there was another red column when she swung the camera back around.

[@jeffostroff]

yes we don't know what it is

[@loufaiella3354]

Speculation: The red usually indicates something to do with fire?? maybe a fire pipe or fire extinguisher??

[@johnbergstrom2931]

Or FDC location.

[@jeffostroff]

I thought that initially but go back and look at the freeze-frame inside the garage, you will see that the fire extinguishers are on the other poles with the yellow stripes

[@patrickmorrissey2271]

I can't see it in the video, but I've seen that in buildings... This building would have a fire alarm main control panel. A building engineer or Fire Alarm Tech person finds that panel, checks all the alarm heads & sensors, does PM's on the system... In case of a fire alarm, Fire Department personnel want to find that panel, and see it, and see where the alarm is coming from, so that they can respond to the right area with speed & efficiency.... I've seen that area painted red many times... I am not 100% sure if that's code, or the FD's want it painted red, or the alarm techs want it painted red... but you see that a lot.... I'm just speculating, but that's what it looks like to me.... It would really be great to find the Techs from the fire alarm company who had the maintenance contract for this building... I'm sure they could shed a lot of light on a lot of things....

[@Phoenix-jw1mn]

@@jeffostroff It looks like most of the red ones have a box with a powerline going up into the roof. I'm assuming these columns had the fire alarms attached to them. I counted 3 of them from this and the past videos and there might be more, it's hard to make out things in that shakey video she taped.Though it's hard to see, they all look like they have what looks like a fire alarm on them.

[@ad8590]

It must have been added after the infamous garage video was taken.

[@jeffostroff]

Yes that would be one explanation.

[@RobbieHatley]

Someone built a huge concrete column, _not_ over a caisson, and in the middle of a driveway? No one would have done that. No, the H-beam simply didn't fall straight down; it fell NW-wards and downwards at a 45° angle because the large columns under it toppled instead of crumbling.

[@samuellourenco1050]

The beam is heavy, but the columns that supported it, in comparison, are very thin. This alone triggers alarm bells in my subconscious, telling my brain that the proportions are not right. And, not to mention, the added weight of the extra column.

[@TeamDoc312]

You're becoming the "Bob Ross" of engineering mysteries!

[@jeffostroff]

LOL! Let me paint you a picture. Think of our happy place in the concrete pit

[@MajorCaliber]

@@jeffostroff I've got a bobby-pin... and a faulty slow-tripping GFCI that you can use to get just the right amount of *BZZZZOT!* for the frizzy perm! Only THEN can you paint "happy little clouds"! :D

[@WApnj]

Playing music over your narration is very annoying.. STOP THAT!

[@jeffostroff]

The music is not over narration it is behind it.

[@WApnj]

@@jeffostroff playing music behind your narration is very annoying.. STOP THAT!

[@MajorCaliber]

Apologies if I missed it in an earlier vid, but what WAS the reason that only a very few garage-level columns had RED-painted lowers (e.g. 86-87, 17-18), vs the usual YELLOW visibility paint? Fire Dept. hydrant/outlets?

[@jeffostroff]

That I do not know the answer to. But I doubt it had anything to do with the fire department because of the freeze frame if you look in fiorello's video from the garage, you'll see that fire extinguishers are on other columns that have yellow stripes. But if you go back and look at that freeze-frame closely you will see the column with the stripe on it inside the garage appears to have some type of switch or other fixture on it so there may be something to indicate that that column has something to do with backup power or an alarm or something just not sure

[@ChiTownDude]

Generally, red painted columns signify some type of fire equipment involvement. Fire extinguishers, likely.

[@brianleeper5737]

@@ChiTownDude I remember noticing that in a Sears or Montgomery Ward department store years ago. All the columns with a fire extinguisher mounted on them had a red stripe painted around them at ceiling level. I wonder if this was a code requirement.

[@whathappenedtomyYThandle]

6:58 87-88 7 is red, 8 is yellow and look like it has a fire extinguisher unless it's something else.

[@alobodig]

@@jeffostroff Maybe it's coincidence, but the ones painted red have fire alarm pull stations on them. You can see this on the columns labelled 16 and 54 in Fiorella's video.

[@VW5767]

It looks like the mystery column started at the H Beam and went up from there to the penthouse. When the collapse happened, it drilled itself into the garage floor and broke apart. I bet if you look at the rebar sticking up from the garage floor, its not tied into any other steel in the garage floor.

[@jeffostroff]

We are still debating this one. I maintain that a column falling could possibly do that, but there is no floor damage from a column smashing into the floor.

[@VW5767]

@@jeffostroff good point.

[@QmeteK]

very interesting video... liked it

[@jeffostroff]

Many thanks

[@AddictedToC64]

I never worked in construction nor have I any idea about how it's done - yet, I am fascinated by the videos that you (and one other channel) share! It opens the eyes of a layperson what to look for and somehow, you present these things in such an interesting and clear way that one keeps thinking about them. I really look forward to your videos about this tragic building collapse. Let's all hope that the true cause will be found by the NIST and that the lives lost this time will help to save others. As we tend to say here: rule books are written in blood. Thanks for your work, Jeff!

[@jeffostroff]

Thanks, I'm glad you liked it!

[@johnbergstrom2931]

"Rule books are written in blood." They sure are. Especially if you're name is Hammurabi...

[@jimgraham6722]

Thanks Jeff, this disaster and your analysis of it has me wandering around my own apartment complex's basement garage and ground level suspended slab parking deck. So far no serious issues sighted but am a bit concerned the local fire engine crew have taken to parking their fire truck on the parking deck loading zone space while they go for a coffee. Not sure it is rated to take such a heavy vehicle.

[@jeffostroff]

I would add my ring camera at it just for that special moment you can make a fortune with that video when it does fall through

[@billj5645]

Generally structures designed for automobile parking, and the design load required by the building code is pretty low for this, will have some mechanism in place to keep out larger vehicles. Many parking garages have steel bars at the entrance about 6'-10" high so a taller vehicle can't drive through there. If there is an area where fire trucks can physically fit, it should be designed for truck loading. That's not to say that it is, but it should be. For instance the drive along the west side of Champlain Towers had enough overhead clearance that delivery trucks could drive through there but there is no evidence on the drawings that it was designed for truck loading.

[@TheKuptis]

Only thing I could think of was that the column that the H-beam was holding up impaled the garage floor as the building collapsed but you kiboshed that idea near the end of the video.

[@jeffostroff]

It is still a mystery

[@Dr_KW]

There's a simple way to test your theory: metallurgical analysis of the rebar compared to the rest of the rebar in the building. Likely it will show you that that column punched through from above and was not placed there sometime between 2020 and the collapse date.

[@ambermay7032]

Mystery column rebar looks to me as having a different texture. Its smoother than the surrounding columns rebar that all have very noticeable ridges. Is mystery column a very recent addition added in to hide or help the H beam possibly sagging or having serious cracks in the underside from additional unknown stress? Work may not have been documented to try and hide that they knew the issue was serious and so keep property prices high/stop residents from causing trouble?

[@johnbergstrom2931]

It wasn't under the H beam in any way it could have carried a load. It was offset several feet, inline with the 'O' columns.

[@jeffostroff]

Well if the column was added later it was not attached to the age beam which felt pretty intact, it's simply outside the footprint of the age game so it would not be holding it up. If anything it was likely shoring up just the ceiling above it possibly through use of some kind of large wood plates or 4 by 4 posts against the ceiling

[@kineahora8736]

@@jeffostroff clearly must have been added after that walk-through video by Fiorella-you can see in her video there’s nothing there at all. So how did they get the rebar to stick up from the garage floor like that?! Is there a piling cap beneath that location?

[@ashleelalasmith2792]

@@kineahora8736 this was going to be my question? Wouldn’t you have to dig up concrete to get the rebar in like that.

[@ashleelalasmith2792]

Work was documented somewhere I’m sure that costs a pretty penny to install

[@GregInHouston2]

This is very interesting. I've read through other comments and replies; not all though as there are way too many. As much as the "spear" theory is discounted because of the apparent lack of damage, it is the only possible explanation. The Fiorella video clearly shows it was not there at an earlier time so a column would have had to have been added between the time of the video and the collapse. If the addition was above board then there would be records and they would certainly have been found by now. While it is certainly possible this could be done under the table since it is out of the prying eyes of anyone official, it appears to me that this location would have blocked access to a lot of parking spaces. Officials could have ordered a column placed there but no one would voluntarily put a column at that spot! We are certain it was not added after the collapse! With all other possibilities eliminated, there is only one left!

[@johnbergstrom2931]

You're like the anti-Sherlock Holmes. Scotland Yard says: "YOU'RE FIRED!"

[@jeffostroff]

Yes the garage gate would keep out prying eyes of inspectors

[@dalelouis4652]

Why isn't there any rebar sticking up out of H beam where vertical column would have been attached? My guess is it was not attached and when the H beam moved out from under it it piled into the floor with sufficient force to not disturb the concrete floor. Makes sense to me?

[@jeffostroff]

It's hard to say there's so much rebar popping up out of that being that it's fairly hard to tell unless you're standing there and waiting through the forest through the trees to see which ones there should be that we need to be analyzing. But yes the fact that a column was sitting on top of that H beam at some point in time must have been tied with rebar you would think there would be some spaghetti-like rebar torn out of the top of that being. It is also possible that when they were removing the rubble they sliced right through it as they did with many columns in the garage floor as you can see.

[@benefitthirteen]

It's interesting that we see surface rust but little if any concrete attached to the rebar; plus what looks to be an intentional section cut from the floor as though at some point they were looking to add a footing. So many questions.

[@jeffostroff]

Yes, it appears to me that when they were slicing off all of the columns at around the three or four-foot height off of the floor, I'm assuming they cleaned out all of the concrete between them but I don't know why they would have done that.

[@andrewbieger5004]

@@jeffostroff I read somewhere that the original construction was stopped midway (money issues?) and restarted. If that is true, the rebar had plenty of time to get rusted, and concrete bonding would be iffy.

[@keithpeacock9282]

You have visual proof that there was no column in the drive way under the "H" beam before the collapse. there is no column base stub on top of the "H" beam in the picture. how thick is that slab floor? I will bet the column is no more than 3' in the ground.

[@jeffostroff]

Slab could be 9 1/2" thick

[@keithpeacock9282]

@@jeffostroff there are a LOT of should be.

[@johnbergstrom2931]

I looked at the CTS plans and the concrete ramp going into the garage is 9.5" thick, the garage slab appears to be the same, although they don't label it.

[@andrewbieger5004]

@@jeffostroff Correct me if I am wrong, but the Garage slab pour would have been done separately (later than) the columns. If that is the case, we don't know the actual thickness unless someone cuts through it.

[@williamwampler7742]

Could this “mystery column” be a piling from below the slab? Maybe the whole floor was punched down by the weight of the collapse and it somehow poked up through?

[@johnb9394]

I would think that it was a column that started above and was driven down in? Weird that it didn't deviate any of the surrounding concrete.

[@cobra02411]

@@johnb9394 I think that is most likely, that it was driven down into the concrete. The basement concrete doesn't look broken up and sunken so I don't think it came from the bottom up. My guess it that the stress is so high that it cleanly punched it through.

[@jeffostroff]

How can a collapsing floor cause a piling to com up? Also the pilings have huge caps on them. Also there is no piling under this spot. Pilings are only under the columns in the floorplan.

[@Pooneil1984]

Saying "I don't know" and "We don't know" so much in your videos is distracting and undermines whatever point you are trying to make. I got tired of such vagueness about half way through and am not coming back. Make a point and stick to what supports it rather than speculating on mysteries.

[@jeffostroff]

That is why I said it has everyone baffled. There are unknowns and many of them. You cam looking for an answer to question for which there is no answer yet

[@stevephillips6106]

Good work.

[@jeffostroff]

Thank you! Cheers!

[@vincenthearne2190]

That mystery Collum certainly must have been an attempt to add support , however the location of it specifically does not appear to be doing any use whereas it is not taking any of the pressure load off of the surrounding support beams . The H collum visibly is not designed properly to distribute the weight of the Complex also a complete disater in this type of design if you add water .

[@jeffostroff]

Plus no piles or pile caps under it.

[@RobbieHatley]

Nope, it was always there; just, not where you think it is. Clue: look at the H-beam relative to the ramp in the diagram. Then look at the H-beam relative to the ramp in the video. Not the same. Didn't come straight down.

[@metatechnologist]

@@RobbieHatley I think this is the likely explanation. It tumbled from above and ended up at that spot.

[@designstudio8013]

@@jeffostroff I found it: S-1 L cap at 01-8.

[@fraidykat]

No. It came from higher up in the building. The rebar punched through the slab (How thick is it under travel lanes, right?) and the full extent of damage is obscured by the pool of water.

[@lshepherd5859]

misdesigned . the diaphragm wall should there in the first place

[@jeffostroff]

I have some ideas on improvement

[@Simonelectricfl]

That looks like it was an electrical panel bank. Emt conduits stubing up out of the concrete. You can see kinked pipe (regarding does not kink) also no concrete around the bottom like you see with other columns.

[@nickpeetros6895]

My theory of the "mystery" column is that the rebar you see sticking out of the slab are the remains of the column which used to bear on top of the "H" beam (BM35) between column lines 8/10 and N/O. I surmise that this column broke free and was "driven" through the slab-on-grade from the force of all of that weight above. When the demo crews were cleaning up they likely cut the parts sticking out with a shear and likely crushed whatever concrete was clinging to the rebar. I beleive that if you pulled on that rebar, a chunk of column will come out. It appears to be in the same exact spot the 1st floor column used to be. When you eliminate all other possibilities, this seems to be the only remaining explanation. The column didn't "grow" out of nowhere. This could also explain why water seems to be seeping up through this column. Nick P, Civil Engineer (EIT)

[@jeffostroff]

You forget that there is zero damage on the floor where there should have been craters or something else if it had impaled into the floor but there is no damage. These rebar rods look like they were intentionally built up out of that concrete floor like it was done by somebody in the last 12 months, since Fiorella shot her video inside the garage in July 2020, showing no column exists where that mystery column is.

[@nickpeetros6895]

@@jeffostroff No, I didn't forget it...there's just no other plausable explanation...in one of the video/photos it looks like there is a hole where this column is and water is coming up from below. This would support this theory. I can't imagine any other way this rebar ended up there...

[@johnbergstrom2931]

@@nickpeetros6895 Maybe human hands put the rebar there. Not magic impalement.

[@markknister6272]

Column was driven down by the weight of 12 stories?

[@loufaiella3354]

Makes sense! There is no concrete around it.

[@johnbergstrom2931]

Did you not watch the video? It's in the wrong place. THERE WAS NO COLUMN THERE for almost 40 years!!

[@loufaiella3354]

consider that there is a column on the first floor that got driven in????

[@johnbergstrom2931]

@@loufaiella3354 No way, not that neatly. The east wing of the building fell slightly to the southwest. The columns didn't spear down into the earth perfectly vertical. Even if they did, the energy from a column busting through the slab would have massively damaged the slab in the impact zone. That slab looked pretty intact and pristine to me...

[@jeffostroff]

Not likely that it was driven down from above, there are no columns directly in line with this one above so this in my opinion could not have come from above. It must have been added from below