Miami Condo Collapse: How A Pool Deck Brings Down Buildings

[@jeffostroff]

⛔⛔ Official Surfside Support Pages, only send aid to vetted support sites! There are scams related to disasters, you should avoid unvetted fundraisers. ⛔ Support Surfside: supportsurfside.org/ ⛔ GoFundMe Official Vetted Pages for Donations to Surfside collapse victims: www.gofundme.com/c/act/surfside-condo-collapse-fundraisers

[@barrywilliams991]

One cubic foot of water and weighs ~62 pounds. A cubic foot of wet sand is ~120 pounds. Add the weight of the pavers and the weight of possibly water saturated planters and it likely exceeds the maximum load capacity of the pool deck slab.

[@jeffostroff]

@@barrywilliams991 Yes that is a lot of downward force, and even more important, it's more important, it is a lot of downward force on cement that is likely nowhere near the rating that it once enjoyed when it was 1st built as years of water and cracking and spawling have taken its toll on it.

[@debs-101]

@@jeffostroff have you seen this video w/ Allyn Kilsheimer inspecting Champlain North? You will like what he says about taking the core sample. (Says it at 2:00, but start it a little earlier.) kzbin.info/www/bejne/jHTSgI2gocSVfa8 I’d be interested to hear your thoughts about him comparing the two structures. He took core samples of the 12th floor (which we know would have originally been poured to be a roof) to see what waterproofing they installed/or didn’t install and is going to use that sample to examine the debris from the South tower. That might be normal, idk cuz i know nothing about engineering but it’s the first time i heard anyone use the north tower to help interpret the construction of the south tower.

[@d.e303-anewlowcosthomebuil7]

@@jeffostroff bad concrete?..it looks sooo chaulky, and it doesnt stick to the rebar in the normal way. Also, is there any pebbles in it? I dont see any.......incorrect building methods, built to minimum, paid off inspector?....planter box added later with no extra support....rust and rot ( lots of water leaks for years).....undersized columns.....what did i miss?.....bad maintenance, too much cost for condo owners( $200k each?)...engineer and co. inspector paid?, to not scare people( reduces property value $200k ea.).......etc..... .... So, no one could just put up some shoring underneath the pool deck, remove the planters, demo down to solid concrete, add structural crete to the deck, and lots more strength to the posts?.....i just shake my head....

[@theaverageDon]

As an engineer, and someone who just got done binge watching all your videos for the past few hours on the Miami collapse, I think you're correct in saying that the lateral beam between the two columns connecting the building to the pool deck is the main contributor to the building itself collapsing. The main cause to me, aside from the columns being very skinny, is the beam not being on top of the column. You essentially then have a zero moment on the beam between those two columns. However, as we saw from the tourist video, that 12×16 column had collapsed to the side due to the pool deck for its own reasons. This would then create essentially a cantilever scenario where the fulcrum is now outside the remaining column holding up the beam. Think about holding a bat by the end as opposed to choking up on it. Which way is heavier? From there, the beam would be pulling the column towards the now collapsed pool deck, creating a torquing moment on column that it wasn't designed to withstand. Thus creating a domino effect and the subsequent manner in which the building collapsed inward, towards the pool deck. Added load on top the column, along with possible years of internal water corrosion to the rear can also be contributing, but the initial catalyst which triggered the building collapse (separate to the pool deck collapse) was that beam losing its lateral support when that 12×16 column collapsed to the side

[@jeffostroff]

good info thanks Corey

[@blunjtnt]

Excuse me but why isn't anyone telling y'all that there's a construction joint between the pool deck and the tower

[@eringemini7091]

I don't know why this condo collapse reminds me so much of a 100 yr old giant( cypress) tree that VERY slowly fell across my front yard. In 2006, here in Hawaii, it literally rained 40 days & nights. In the mountains, where I lived, it rained 8 feet during that period. I recall how the 🌳 made the weirdest noises, as the wood cracked/ broke, as the ground around it gave way over a series of weeks.That being said, I wonder if the condo inhabitants heard sounds, or groaning in the weeks or months preceeding the collapse? Or, if within individual units, there were odd noises of the building settling?

[@nopenotgonna175]

As a resident of a (second attempt at) a high-rise that collapsed during construction, thanks to your videos I pay much closer attention to the concrete in the parking garage than I used to. The garage looks pristine but I do throw a little side-eye at the pool these days. I hold on to the hope that the towers survive if the pool deck fails.

[@janegilmore102]

For putting all those drawings together. Now that’s dedication!

[@jeffostroff]

Thanks for the love Jane!

[@froter1]

I want to personally thank you my friend , for being so very thorough ! Your analysis of this building and it's construction and defects in construction , is right on target ! I have viewed and listened to other engineers and their perspective of this building and possible failures that might bring a building down . I have to say , most of them leave me with more questions than when they began . I'm in construction and I have been for 50 years , both commercial and restoration. And for the past 25 years , concentrating more in building restoration and historic restorations. I have to say , I would definitely , without a doubt hire you to engineer any building I have worked on are will work on in the future . It is very refreshing to see someone with your skill level and knowledge of construction . Again , thanks so much for your excellent analysis on this building . Sincerely , Joe Guest

[@cliffordpenn7981]

Comment on sloping of pool deck: he talks about this from engineers letter at 27:00. I Have seen this error done before. The original architect designed the deck with a slope to drains. On a job I saw years ago, a pool decker had a contract to install paver stones. He didn’t like the slope because his paver stones could not sit nicely on the slope so he put in a skim coat to “level” the deck before he installed the paver stones. His job looked nice afterwards but the owners complained to me that now the rain water no longer drained off his pool deck. He would have to take push brooms to push the water off his pool deck.

[@mowtivatedmechanic1172]

I’ve also seen the same thing. Also clogging drains in the process.

[@ivosan11]

I used to live in a building with a very similar structure and also deck issues. From the early 80s as well. But there was a key difference: the deck structure was independent from the building. Instead of having two columns 20 feet apart like Champlain South, each structure ended with its own columns just 2 or 3 inches from the other and some flexible synthetic compound to fill the gap. Had the deck collapsed (and maybe someday it will) it would not pull the building with it

[@raven4k998]

it just goes to show how everything can be connected in ways you wouldn't think when they get built that is how a pool deck can take down a condo building

[@nancylloyd1183]

Absolutely fascinating. It seems like Jeff Ostroff's analysis is just nailing it with the information he has available. About the palm trees that were removed...it brings to mind the scenario when characters in movies are impaled with something -- a sword, for instance -- and someone just yanks it out and the person is pretty much ok. In real life, you're not supposed to remove the object if a person's impaled because of the damage it'll cause. So what if removing the palm trees did more damage than the trees themselves could ever have caused?

[@ler3968]

For the non-engineers here, you do an excellent job of presenting the details and graphics about engineering variables that could be factors.

[@davehutchinson773]

Working in construction almost 25 years,your explanation has so many contributing factors,which are most likely cause of the failure,negligence,shoddy repairs and failure to see the urgency of repairs needed to fix this resulted in catastrophe...

[@jkhtravelrn]

Excellent video. Your memory and attention to detail is humbling to those of us who thought we had those qualities as well. I’m really REALLY enjoying your channel.

[@Seashellsbytheseashore21]

Thanks for posting these. I know nothing about what goes into creating buildings, but I am consumed with wonder/sadness in regards to what happened in this tragedy and am learning so much due to your insight.

[@Jamie-zs2bl]

As an epileptic, THANK YOU SO much for this! I can now watch the part regarding the palm trees. I'm glad you realized the problem and corrected it. 💚 Says a lot about you as a person and content creator!

[@jeffostroff]

You are so welcome! It took 2 hours, but it re-rendered nicely

[@Jamie-zs2bl]

@@jeffostroff that's a long time. Sorry it took that long, but I Definitely appreciate It and I'm sure others do as well!

[@mariatamburro]

@@Jamie-zs2bl I agree. He changed some issues and inconsistencies in other videos and admitted he made a mistake. Very cool dude.

[@paedahe4975]

@@jeffostroff Great job Jeff. Your one class act. 👍

[@SmoresySmores]

I was trying to write my comment in response to yours about our new found interests in structural engineering during that part of the initial upload. I kept copying my comment and closing the app because I thought it was just my phone being weird lol... not going to lie I closed and reopened the app/ the initial upload like 4-5 times before I was like maybe it actually is the video itself! 😂 Not sure if you’ve watched the videos on the Building Integrity channel but if not I highly recommend you do. Both that channel and this one do an amazing job breaking things down while keeping it simple enough for just about anyone to understand. They are both so informative and engaging I just can’t get enough of their content!

[@ChristopherATX]

Ironically, I just got to the palm tree section on the first video and had to turn it off then I saw this one posted with the correction. Thank you sir! Good job on all your videos. I don’t get into all of this building stuff but this has been very intriguing and you keep me coming back!

[@sherribrawn3757]

I totally agree!! This stuff is greek to me, but having someone break it down, and explain it in terms I can understand is really appreciated.... ;)

[@amymusick5455]

@@sherribrawn3757 Yes! I had no idea all the computations involved for architects/engineers/construction. 'not sure if that makes me feel safer or more paranoid! We have stayed in many (family owned rentals) condos on Clearwater beach over the years. I'm going to stick to my trailer out in the boonies from now on!

[@estherdelaney9819]

I was watching your videos and listening to your every word when suddenly I couldn’t keep my eyes open. I finally gave in to the soothing sound of your voice and went into a sort of relaxing period that I can’t say was sleep, a semi awake sleep maybe. You have a great voice.

[@kristensorensen2219]

This is what journalists once were all about!! Thank you!!👏👏

[@jeffostroff]

Thanks you Kristen!

[@tomsparks3259]

Jeff is a construction specialist. Journalists are most often generalists. A typical journalists wouldn't know where to start.

[@Veronica.John10-10]

exactly, not like CNN or MSNBC is today!

[@kimberlyperrotis8962]

Very informative videos on the sad disaster. I’m a geologist and worked during my whole career for a big, international engineering company. I’m always very interested in listening to what engineers have to say, and your discussions are very good, thank you. I appreciate you taking the time out of what must be a very busy engineering practice. The more we all can be educated about engineering and construction, the better. It’s a complicated built environment we live in today!

[@jeffostroff]

Thanks, glad to help!

[@robinwells8879]

A disaster rarely if ever, has a single cause. Usually there’s a series of coincidental issues that combine to lead to the ultimate failure. The Swiss cheese analogy is often used where all the holes have to line up for disaster. I will wager that some holes are incorporated in the construction phase and others were added along the way. Only the totality was sufficient for disaster. Exponentially is not a word added lightly in a contractual document a bit like “time is of the essence”. 😳

[@FattyFPV]

Vanished from the media cycle now. You work has been wonderful to follow.

[@Jamie-zs2bl]

Ooh. And those palms will really do some damage to the concrete under them (if there's already cracks in it)... my mother in law had some in her yard and they were also in planters. The roots broke through the planters at the drainage holes, grew under the concrete pool deck, cracked it more, and she ended up having to redo her whole pool deck as well as do new plaster on her pool because of the damage. Just thought I'd mention that. Not saying that is what happened here at all.

[@punker4Real]

We see cracked concrete all the time here in California from trees roots...

[@Jamie-zs2bl]

@@punker4Real Yeah, I know. I only mentioned the palm trees because he was talking about them in the video. If he'd been talking about oak trees I'd have mentioned the one at my house that lifted and cracked the sidewalk.

[@jeffostroff]

@@punker4Real yes we see it too

@@jeffostroff , is there a shred of evidence that palm tree roots were growing through the planters, and then....? So far I haven't seen one plausible suggestion of it. Just a lot of wild speculation. Meanwhile, in the photos from above of the palms in the planters -- do they look healthy to you? I can tell you from my building's experience that it's not easy keeping palm trees alive in such an artificial planting scenario, much less, healthy.

[@tompastian3447]

A town house in Hialeah I work in has a couple palm trees planted right in front of the house. One tree root grew under the floor of the front bedroom, cracked the floor tiles. The owner refuses to blame the palm tree, and thinks blasting from developers west of the area caused the tiles to crack. Don't underestimate the damage that tree roots can cause.

[@michaelyoung4373]

I like the video. If your Diagram is correct, I can see a few potential problems. 1. The beam under the pool deck needs to carry the pool deck slab edge because it does not sit on top of column L10. 2. All of the columns under the building are 16" x 16" including those at the perimeter Grid Line L, which are carrying the edge of the pool deck and the added load of the building cladding system. 3. How were the beam, columns ground floor slab and pool deck rebar installed and concrete placed? The sequence of those works are critical. You need to do a video on that. Were the basement columns cast first? Were the basement columns and beams cast together? Were the columns done first and beams cast with the floor slab after? Were the floor slab and pool deck cast together or separately creating an open joint for water running down the face of the building and into the joint. A review of the sequence and the rebar schedule would give you more information.

[@missmelodius]

Thank you for reuploading. Glad to see all the work you did on this presentation and to understand the questions you are asking.

[@jeffostroff]

Glad to help Melodi!

[@celestialdragon3989]

I know nothing about construction, building, blueprints etc but I’m mesmerized by these videos, as u dissect each time. This is a huge puzzle to figure out but you’re really putting your all into it! In beginning, I only heard about a flat pool & sunny day flooding. Think it extends to much, much more than that & you will figure out this puzzle 😃

[@honolulublues5548]

Thanks for the reupload. I had to stop the video because I have a seizure disorder. You and Building Integrity do a very good job without access to the site.

[@jeffostroff]

this one will be better!

[@jewllake]

Because of your videos I now refer to road barricades as Bob's Barricade. People look at me like I'm crazy.

[@AP0110Music]

I don’t disagree with any of the theories you are exploring and explaining. But I just want to mention as a videographer that the weird bendy artifacts you are unsure of in screen grabs from the garage cellphone video could also just be banding from the fluorescent lights or some rolling shutter from low frame-rate video from walking Cellphone in a not so well lit area…Im not saying what you are stating is wrong..just dont want you to overlook how inaccurate YT compressed cellphone video screengrabs can be with weird artifacts. Keep up the great work and thank you for the great uploads providing great insight.

[@davidpoulton7694]

As a video editor myself. That looks that way to me as well. Cellphones lack contrast details.

[@katenunyabizness9221]

I agree. If you look in the background of that shot, column 18 looks pinched in from the car roof height to the ceiling. Column 17 looks stepped just above the number which I am fairly certain is a trick of the lighting.

[@stormcherry6064]

@jakesgrl6378 yes, he does need to go cool off - and it doesn't matter where he is from.

[@dukeofhaas]

@Ra Akhanaten Amazing how one comment can change the entire focus. In much of North America, many viewers believe that your comment was rude. Yet the farther East one travels, many believe it is rude to publicly boast about oneself. Instead of personally inserting oneself into the topic of the original video, perhaps more people, regardless of their cultural history, should contemplate the subject at hand, which in this video concerns looking down upon the open grave of nearly 100 humans. "Life is very short and there's no time for fussing and fighting my friend." (c) Lennon/McCartney

[@shiny593]

"Lens artifacts generally worsen as you get closer to the edges of the frame. And the sprinkler pipes, being much closer to the top of the frame, would therefore be more distorted, if it was an optical issue." A statement that I found in the comments of the video from 4 days ago. Do you agree with this statement?

[@sebastiannai4381]

I'm loving the series, great investigative work. I'd like to see you and Building Integrity colloborate. It's obvious you are watching each other's videos and already collaborating in a sense. The epoxy injection port was a giveaway, and his videos also have similar instances of gaining clarity from yours.

[@jeffostroff]

They are true pros who work this stuff every day

[@coeneschamaun1735]

@@jeffostroff and evidently the forensic building failure engineer, that the city of Surfside has hired, has not been allowed to examine the site, or any materials from the site. What's up with that? Local police say it's a "crime scene". Removing all the actual materials, and not allowing an expert to examine them "in situ" as much as possible, is wrong, and possibly political??

[@jeffostroff]

@@coeneschamaun1735 NIST has the lead on this. Now that they cleared the area they should let him into the site, but too little too late all evidence is being analyzed by NIST at off site locations. IT is their party and no one is invited.

[@LanceHKW]

Thanks for uploading this version - had to watch again as there are so many interesting details you gave us!

[@Stellra52]

I just want to say I love how thorough you are. I am so tired of just hearing blurbs and sound bites about this.

[@firewalker1372]

This has been a very great series, if you have no problems with this. I would like to use this series with my crew at the firehouse when we discuss building construction this week.

[@jeffostroff]

would be awesome!

[@firewalker1372]

@@jeffostroff we do not have buildings in our city this large, residential anyway. But we do have many two and 3 story buildings that contain the “Stars and Bars” or star anchors in our city. I would definitely like to incorporate these into my discussion, thanks man and keep up the great work.

[@DARWINZOO]

You know we sit here on the web looking at things. And then suddenly it's so worth it

[@gracieg7601]

@@firewalker1372 I want to tell you as you as a fireman, thank you for whst you do. Firemen have come to me at the absolute worse time of my life. I hope you know and please tell your fellow firemen thank you snd God bless you all! I alwsys pray that y’all are safe when your working a scene like this. My home growing up wasn’t far from a fire hall. Like 5 blocks. Since we lived so close and my dad made Friends with them. My dad as he got into his 70s got memory issues like dementia. He liked to walk but now and then he’d get lost but he knew where the fire station was. He would go there and tell them he was lost. So he’d give them his drivers license to show them his address. They would put him in a fire truck which he loved and they’d bring him home. Lol my dad was quite the character. Anyway, he got on his roof one day and he knew it wouldn’t be long till he couldn’t get up there so he talked my mom also around his age into climbing up there too. But mom got scared. So the neighbors called the 911, and they came over with a bucket truck and got her down. So thank you guys for being the best of the best. Theres other times not so pleasant when we needed firemen. God bless you all for your caring.

[@gracieg7601]

@@jeffostroff I found thus video of collapse from inside one apt. kzbin.info/www/bejne/Z5S3oJygopusnbs

[@leavesongrass]

Thank you for this! I love the way you narrate it-sort of like you are whispering in our ears! So interesting.

[@jeffostroff]

glad to help!

[@Paul_Wetor]

One thing I don't understand about the construction of tall buildings is that the box structure seems to be the same size throughout the building, which distributes the load. But why doesn't the base have fatter pillars? It has to carry the weight of every floor above it. Why aren't the pillars like a tree, which is fatter at the bottom? Or are they really thicker, but I can't see them?

[@fraidykat]

MONEY. Thinner columns are cheaper and you can get away with the error for 40 years.

[@beehaven9949]

There are like a tree in terms of the compression load changes. Every 4th floor they go down 1000 in fc. There was a column that was thicker in the basement and skinnier on top (column type B was 24" x 60" and had a column type A on top 24" x 24" starting at the lobby) but these were changed to having a 24" x 24" all the way. I guess it makes it easier for the concrete guy to pour the same thing in the same forms over and over and only the concrete type in the truck changes to a lower compressive strength as they go up the floors.

[@eulinpetit-woodyear6816]

The construction of a building is not only an engineering exercise but also one of economics. Having a different and unique form size for each floor may not prove economical. From an engineering standpoint the weight of the entire building is transfered to it's foundation. It is here you see an increase in the size, number or type of column but it's no longer called a column but instead called a pile.

[@fraidykat]

@@Mike-bm6cf Grade and thickness of concrete both have a lot to do with what cracks.

[@fraidykat]

@@Mike-bm6cf Oh yes very, very much. If you use overly watery concrete, it will have lower tensile strength. If you make a column 12" instead of 24" thick, it will have less strength. If you embed the rebar 1" instead of 3", the concrete will crack much easier. All three scenarios lead to concrete work that has a greater probability of cracking and spalling. You're playing the stupid game contractors play when they cut corners to save money and expand profit, the stupid game if "everything cracks and spalls eventually" game.

[@jean6061]

Why didn't the rebar in that photo of the garage ceiling have additional rebar attached to form a grid? I only saw parallel pieces of rebar. Was that acceptable at the time of the build?

[@oneeight5781]

Rebar goes in both longitudinal and transverse directions. The ones you see are closer to the surface of the slab. The rebar in the other direction is just beyond the ones you see. Additional corrosion and spalling will eventually expose those as well. Rebar is always in both directions in a grid pattern as you mentioned; although one direction may have more depending on the span of the slab in that direction.

[@JP-lq6us]

Thank you, was happy to help. You have a Fantastic series. Love your videos

[@vinscully4283]

Thanks for your kindness and feelings of the loss once ,God will strengthen we all to keep moving, I believe you’re lovers of Dodgers baseball 💙🏈⚾️ and it be great to know you, The voice of Dodgers Vin Scully: reach me on Gmail sections Okay : [e-mail]

[@billrutledge2441]

Thanks for making your cursor more visible. Makes it much easier to follow your narrative.

[@booterone1]

Thanks for the re-load. I thought it was my poor connection! Great video.

[@ketelin4285]

I will disregard the issue of the 3/3 excavation . It let the waterproof membrane in place so from the water "point of view" the deck was just like before . What i'm interested is how rebar got pulled out cleanly out of slabs . Usualy the slabs break and chips of concrete hang onto the rebar . (LE - i see you observed that too , nvm)

[@fraidykat]

Completely inundated by water, the rebar corroded and then the water washed out the corrosion. End result, the rebar is smaller than the hole it occupies...

[@jeffostroff]

yes I had pointed out a few times how even on the rubble pile every single pie of rebar was stripped clean

[@kellyanneree3252]

The architect noted that the waterproofing membrane was in a failed state! It wasn't holding water which is why all the water is in the garage. The pool deck was hosed down DAILY! With a failed waterproofing membrane underneath!

[@T5RABBIT]

It appears to me that the rebar pulled away from the ceiling is from the rebar placement in the slab, laying directly on the form when it was poured, at the very bottom of the slab. For rebar to be effective, it must be a few inches above the bottom of the slab. In my opinion, it pulled away cleanly because it was not installed correctly.

[@goldteethman8720]

@@T5RABBIT Use to do concrete "Tied Rebar" Thats what I was thinking. Plus water laden concrete bad combo

[@musicalgamer354]

Awesome video Jeffostroff! I think you’re spot on with your theory of the pool deck sample, column 27 collapsing, and the beam warping and collapsing, which led to a failure of other columns. Your video truly sums it all up as a combination of issues that contributed to the collapse. I’m curious if the beam in the sister building is also warped… I want someone to go and check it to see if it’s having the same issues or not!

[@Wazupu]

“I want someone to go and check it”, L0L.

[@rogerwilks6250]

your videos are absolutely awesome. absolutely hooked. clear and easy to follow and exclusive content. I think you will solve this long before anyone else. God bless everyone involved with this horrific collapse.

[@fuyu5979]

Jeff very interesting analysis of the condo collapse. So many unanswered questions as u go methodically through ur analysis. Kudos for ur video. Anticipating ur next one.

[@franks471]

I've watched a number of videos from different people on this topic and I've learned quite a lot. I was mostly just curious. I'm figuring out how the lateral forces affected the columns, and while true if they were thicker it would have been more stable, the same problems were all there. My totally unprofessional and untrained opinion is the actual collapse of the building was due to lateral forces acting on the columns. They were too thin, too long, and too damaged once the pool deck collapsed. As far as design flaws, I think Jeff nailed it. His point on the continuous pool deck slab makes absolute sense. I feel smarter having all this explained to me. Thanks :)

[@jeffostroff]

yes, if they had not connected 2 of the columns via beams to the bool deck or made an isolation seam between pool deck and building, the pool deck would not have caused the building to collapse.

[@ACCinematography]

any word on the security camera footage from inside the building? are there possibilities of it being released to the public in the future? or is the footage gone.

[@andrewbaans7400]

Either the memory cards would have had to survive or cloud storage was used.

[@ronbennett7885]

Also, security videos from other buildings aren't available either. The short video showing the collapse appears to be a video capture off a monitor with a cell phone. It's likely all video in the area has been seized by authorities. Sure, copies probably exist on removable media, in the cloud, etc, but building managers / security companies have likely been advised to not release them. I understand why, but doesn't inspire confidence. Makes people wonder if the truth will ever be known; what are they trying to hide. To be clear, not saying that's happening, but is the impression some are getting.

[@VictorNewman201]

@@ronbennett7885 "Seized by the authorities" doesn't inspire confidence these days!

[@jeffostroff]

I filed a request today with Miami Dade PD, we'll see how far that goes. I looked at tourist's hotel across the street, shocked to see no cameras on the side of the building

[@Dilberto88]

@@jeffostroff - wow, that hotel across the way stood longer than Champlain Towers South!

[@imconsequetau5275]

I really appreciate the awareness you are bringing to the public. What brought the building down _with most people inside_ was the *decades of delay* in repairing the structural cracks, and *our general lack of awareness* of wide concrete cracks, and what widening cracks mean. Hopefully, a general public awareness of these warning signs will prompt more competent response in the future. These *wide cracks must become commonly recognized as a severe structural failure of concrete, and a potential prelude to complete structural collapse.* The general public needs to become aware of the consequences of ignoring widening concrete cracks. We need to become very alarmed and even outraged when wide cracks, leaks, or even _spalling,_ are observed.

[@nancylpr]

I agree, most accidents are not caused by just one thing. It's usually a combination.

[@theylietoyouall.5051]

Swiss cheese model I think they call that. I could be wrong though.

[@marlorodo]

Watch this video! Champlain Towers South-Crane Collapse (June 9, 1980)

[@MrMaxyield]

Oh it's one thing... Money 💰🤑

[@markallen4514]

Jeff: Thanks for the great content. As someone who’s been involved with a lot of construction failure litigation, it’s fascinating how this came about. One thing that struck me is the complete absence of concrete on many of the columns. I’ve seen this once before-on a large harbor harbor wharf. There the “culprit” was actually waterproofing. The water was kept in the concrete by the waterproofing and degraded the concrete. Ironically, the waterproofing was a fix to minor spalling and instead it ruined the entire structure. I’m wondering if that could be something like what happened here?

[@donnasantiago5016]

Thanks for fixing the video!!! I watched the end and heard some more, very interesting info. Thanks again!!!

[@jeffostroff]

Awesome, thank you!

[@flaw3dgenius222]

Love these videos... Got no idea how i from Glasgow Scotland managed down a rabbit hole on this condo collaspe but im addicted to all vids about it thanks to Jeff and KZbin algorithms

[@jeffostroff]

Thanks, glad to have you visiting from Sweden

[@marklittrell5650]

Has any video from the garage or pool deck camera's been released? Any chance a driver may have hit the column M10?

[@nancyswan2056]

My thought also.

[@captinbeyond]

That was the first thing I though of as well when I saw pictures ( pre-collapse) and the very support columns that failed are depending on everyday driving around them not to bump into them. If someone will ill intentions took out only a few of these, ???? ?And these beams seemed small relative to what you might want to have in proximity to where traffic is constantly prone to hitting them

[@ianchafer8023]

Hi Jeff. I really hope you read all your comments, because im not sure if I spotted something. If you stop your video at 21:56, you can see what I think is the pool deck drains. There's one at the top of the screen near the two white column's going up the building, a second going diagonally to the left on the screen near the cut out inspection section and a third one near the bottom left of the screen. Defiantly the top one and the bottom one have standing water around them from what I can see. Also there's an other one on the right of the screen behind the second planter on the right, but I don't see any more around the pool deck area except those ones. If there is standing water around the drains, they must be too high! Would water then leak around the drain pipe if it's not sealed properly and get into the concrete deck? I hope this might be helpful. Your videos are very well done for such a sad event. Cheers. Ian chafer. Ottawa, Canada.

[@deekayvixen]

Thanks for correcting the video issue! Very insightful and thorough analysis.

[@jeffostroff]

There was an issue on the first attempt at uploading this earlier tonight with the codec in the rendering process of the video processing software causing flashing and glitching. I re-rendered the video and re upload the video under the same after 3 hours, it works perfectly now.

[@sheryldupre-mercier7607]

Thank you so much for making these videos. I find them so informative. And your voice is soothing 🙂

[@jeffostroff]

Glad you like them!

[@vinscully4283]

Thanks for your kindness and feelings of the loss once ,God will strengthen we all to keep moving, I believe you’re lovers of Dodgers baseball 💙🏈⚾️ and it be great to know you, The voice of Dodgers Vin Scully: reach me on Gmail sections Okay : [e-mail]

[@gregoryagogo]

Would permits be required for added planters and the brick covering work on the deck?

[@jeffostroff]

I would think so, we showed the permit for it at the end of the video from 1996 when they were added.

[@beehaven9949]

I don't think these "Building" folks are the sharpest tools in the shed. After the first general contractor resigned on this job, I think they tool the design as a building suggestion rather than actually follow it to the letter. They apparently rely on the designers to inspect the construction is done per the design and do not check it themselves. They get letters from the designer that construction is per the design as far as they can tell or to the best of the knowledge (and don't blame them if it isn't). Cranes fall down during construction. Radical foundation pile change during construction. So the Building folks just rake in the permit fees and really don't enforce. The one enforcement seemed to have been the cease and desist on adding a 13th floor, but that was overruled a few days later. So it is a Building Department In Name Only (BDINO) and they are really not equipped to be issuing building permits.They are the ones allowing these falling down building that kill people to be built and to remain occupied until they fall down. Adding six palm planters looks like its way beyond their ability to question or to stop it from occurring (they can't even stop a 13th floor from being added).

[@oscarmarban5163]

Hey Jeff I know this is a serious video but I wanted to take the time to thank you. You have saved me tons of money in home renovation projects within the last couple of years. I appreciate your work man!

[@ronbennett7885]

Wonder how much, if any, of the security videos from the collapse will ever be released to the public. Also, the city hired engineer can't get access to the site nor even concrete samples. So many questions. Hopefully, there's more clarity soon. Your videos, while speculative in some regards, are helpful. Keep them coming.

[@rongeremy6970]

There is footage from a security camera, does show flashes from explosives,

[@notgreatnotterrible48years63]

The security video has already been released man

[@CaptainCaveman1170]

@@rongeremy6970 Not explosives. This was not a controlled demo. You have to jackjammer explosives into many columns and run cables all over the place. Every floor was occupied and there was no place to "rig" the building with explosives. The only plausible way to bring it down "secretly" would have been a van in the garage, but we have video of the garage after pool deck collapsed and there was zero debris field, which there would have been had a van been blown up in the garage.

[@michaelimbesi2314]

That "rippling" on the column is probably shadows of the pipes on the ceiling being cast by the light nearby. I don't think it's anything to do with the column itself.

[@lifejourney48]

You are so right about that beam it look like it is leaning in

[@debrazawacki923]

I have learned a lot from your perspective but where is all the water coming from to weaken the columns and the roof ( deck )...

[@SuV33358]

Rain, they get lots..,.years and years of hurricanes and salt water spray from being so near the ocean

[@jeffostroff]

If the waterproofing on the deck wear down, water soaks into the slab, gets to the rebar, rusts the rebar, it expands, slab cracks, not you have water flowing to under side in the garage.

[@deedewald1707]

ACTUALLY waste water from running AC units in home units !

[@sylviabeam9343]

I'm so amazed how intelligent of a person you are. How you are able to get spot on the possible cause of this collapse. Thank you for your time helping others to understand

[@williambunting803]

In you image at 0:41 on the far right you can at least 2 more buildings down the street with identical features, so figuring this out is very important. I’m still certain that the parapet fell first, that and this building seems to have very little reinforcing, …. There don’t appear to be any joists or column to slab joint buttressing under the pool deck slab. My experience is with ferro cement boats, inspired by Pier Nervi, where the vital elements are the reinforcement and the cement mix, particularly the water cement ratio and the cement application to the armature. Get any one of those wrong and the integrity of the whole structure can be compromised. Cement has very little tensile strength so it needs steel for longitudinal structural strength, but vitally it needs local “strapping” reinforcement to keep the cement bound together so it doesn’t crack and crumble. Crumbling is what you can see signficantly in the rubble pile.

[@jeffostroff]

I would love to get into that "north tower" it is 3 buildings up, and built with the same floorplan as Champlain Towers south

[@michaeltranchina6358]

Excellent research, analysis and questions Jeff! The questions you are asking need to be catalogued. No doubt there was a number of small but significant chain of events AND conditions that brought this building down, and I think you have already uncovered many of them... Keep up the great work...👏👍

[@lynng233]

I believe it was a 'perfect storm' of problems but I'm seriously wondering about the integrity of the concrete mix.

[@MainMite06]

I stopped reading forward when I heard that the building used a *basement parking lot* - IN FLORIDA (Read: limestone under soil=tonnes of ground water!)

[@mariusvanc]

Pretty sure the palm trees didn't help. Palm trees are known for growing very deep, strong roots.

[@comment6864]

Very nicely done video. Keeps moving along at a good pace, not too fast, not too slow, with clear depictions of the ideas

[@jeffostroff]

Glad you liked it!

[@AmauryJacquot]

one of the essential issue was that the pool deck was integral with the building... they should have been build separate with a sealant join in between

[@davidperets9997]

agree, another right conclusion.

[@cproteus]

And an expansion gap.

[@davidschwartz5127]

Somewhere along the southern building face with the 5 BMA's tied into the pool deck columns and then the building columns, the pool deck, and building must have been tied together. It could have been possible for the pool deck to rise up slightly in a teeter-totter action before dropping and causing rapid tension than compression waves like an earthquake which most likely causing considerable damage to the building's concrete structure and no longer had the strength to hold that section up.

[@MatTZI014]

Yeah I agree. I think it was a way that the developer at the time could "legally" save money and costs on construction but didn't think of the negative implications it would have years ahead. Just because it's legal and it's the bare minimum does not mean its safe and sound engineering construction.

[@dr_shrinker]

According to the tourist video, the pool deck fell and the building was unaffected. Something else must have caused it. I would think the deck did shear cleanly from the main building. Based on the evidence in the tourist video. However! You are correct when it comes to the West end of the building, where the cars were laying on the slab. That part was a corporates into the building. It’s very puzzling for sure.

[@nicholasconder4703]

In the latest Building Integrity video, the host pointed out that, based on fracturing of the slab cores, the concrete slab was likely delaminating below the rebar. This means that the bottom 7-8" of concrete (about 3/4 of of the slab) was pretty much unsupported. The dangling rebar in the photo at 28:40 appears to support his hypothesis. If this is correct, then the leaks and lines of stalactites would indicate the cracking on the ceiling of the garage were tension stress fractures, suggesting the slab was already sagging. This delamination resulted in a punch sheer that didn't leave a cap on the top of the columns (the slab rebar didn't break, it bent around the column as the slab fell). That still doesn't quite explain what lead to the catastrophic collapse nor the time delay between the collapse of the pool deck and the building itself? I don't know if the pulling sheer from the beam would accomplish this. Also, did the water creep seen at the base of most, if not all, the columns also represent a problem that contributed to the collapse (weakening the column bases). Was the proposed delamination of the slab caused, in part, by an improper job of pouring the concrete? Guess we will have to wait for more information.

[@mariatamburro]

Have you seen the video done by rako studios? He gives you a lot of credits and he does an EXCELLENT job on the photo/video editing. Maybe you could collab with him. I would love to see your analysis of the enhancement he does. I also would love to see him enhance some of the higher resolution stuff you have.

[@amymusick5455]

Wow that picture from across the street really gave a lot more detail when lightened up. Thanks for sharing!

[@paulschane5865]

At the 20:08 mark in this video you show a zoomed in shot of an aerial photo of the pool deck. In this photo you can see a large rust colored stain around what appears to be a drain. Would this drain by any chance go to the pipe in the garage with the rubber boot patch ?(handyman special) Because I asked myself why would they cut out the original PVC? I'm assuming it was an attempt to unclog the drain with the large stain around it which was clearly backed up for some time after unsuccessful attempts were made to do so at the pool deck level such as snaking it or the use of chemical drain cleaners (the latter may account for the stain). If the drain was not functioning even more water (now possibly containing corrosive chemicals) would flow to the 3x3 excavation or seep through the pavers or go somewhere else other than where it was supposed to right? Also the planter to the right of the one that has the 3x3 excavation at its base has about a dozen pavers or tiles that are a different pinkish color (the color of the tiles before years of sun perhaps stored away in a maintenance shed?) The different colored tiled area is the exact same size as the excavation site. Could they have made an excavation in that spot and replaced the tiles with new ones? Your thoughts?

[@Sahlstrom1550]

Can you explain how the other Champlain Tower building has been inspected & is in good condition? Has anyone evaluated a difference in construction or maintenance?

[@jeffostroff]

Difference in HOAs. They reacted quicker to fix their problems in the past, an I think they recently painted their building.

[@Sahlstrom1550]

Did you ever hear if Champlain Towers north is also sinking, similar to CT South?

[@robi4387]

@jeffostroff at 6:29 the deflecting beam is a concern. More so the extensive cracking near column heads. Was it punching failure of the slabs or did the columns fail due to corrosion or vehicular impact? A column of 12" x 18" should be adequate if correctly reinforced but original drawings only schedule 4 main bars and this is not sufficient for UK practice. However, more important that the bars are bent over at the top and anchored into the slab. I've seen in video clips a lot of straight bars at the ends of wrecked columns. 4000psi concrete is weak and not very durable in a salty chlorinated water environment.

[@jimsuard]

Thanks for fixing the glitch so fast.

[@drlisa3]

I’ve always wondered about building pools on ground that is below sea level. For example, the extra precautions taken to make it safe, as well as the maintenance overtime. Not to mention, adding foliage around the pool which creates large roots, (e.g., Wheeling willow trees in the Midwest around our homes - sewage drains).

[@abe39]

I thought the first upload was for a private audience only. Thanks for posting!

[@jeffostroff]

There was an issue on the first attempt at uploading this earlier tonight with the codec in the rendering process of the video processing software causing flashing and glitching. I re-rendered the video and re upload the video under the same after 3 hours, it works perfectly now.

[@d.t.4523]

@@jeffostroff Thank you. 👍

[@gracieg7601]

@@jeffostroff thanks. I saw that too.

[@RosettaRedfeather]

This is awesome - amazing analytics! I wanted to say that I thought at first that the “ripples” in the column were shadows from the red sprinkler pipes! Looks like contractor cost-cutting and incompetence cost many lives and much grief.

[@hmbld1]

The 1/2" Sprayed urethane under the slab for the building is for insulation, not water proofing.

[@stephenfallis9374]

Fantastic video, best iv ever seen on a epic event that needs explaining. I feel like I was invited to listen to professionals sort thru all the facts that caused so much trauma to so many innocent lives. Absolutely brilliant. Thanks

[@EstorilEm]

In that vertical photograph (recent one) of the pool deck, it appears that someone had removed an additional 3x3 section of pavers next to the planter to the right of the one in question here (pavers look new and the dimensions appear exactly the same). I’m curious if another exploratory study was done there in the past. Can we tell how tall the building was during the crane collapse? It’s almost impossible for a crane to fall *without* striking the building. Also can’t we just go into the parking garage of Champlain towers north and see if that beam is on top of the columns? It’s almost like they thought they were one column over then realized that the beam needed to be there, but the column was already cast - so it was added to the sides. This is unlikely as rebar would need to connect the two still, but like you, I just don’t understand it’s implementation.

[@raver208]

So insightful...thank you for creating these. My wife & I had our bathroom completely remodeled 7 months ago & I noted the efforts by the ocntractor to make the shower floor slightly concave to direct water to the centered drain. Mold/moisture resistant sheetrock also used behind the tile. So true about "never knowing what lurks behind".

[@k53847]

There are a few monolithic poured beams connecting the pool deck to the edge of building. So if the column under the pool deck shifts it will pull or push hard on the critical structural column. There is also an paywalled article in the Miami Herald implying the original structural engineer had some questionable events in his past. apparently mostly involving job-site supervision.

[@jeffostroff]

Miami herald charges to read articles, can you get me the name they were talking about?

[@k53847]

@@jeffostroff What I can get for free: Structural engineer Sergio Breiterman... Breiterman’s engineering firm, Breiterman, Jurado & Associates, www.sun-sentinel.com/local/miami-dade/fl-ne-mh-surfside-engineer-problems-secnd-building-20210718-m6ogb77fjfhmpnvzbro3crs4ue-story.html

[@PaulJersey]

Great job Jeff. Thank you for sharing. 1) I watched some of the rescue/recovery videos and the NIST guys (men in black, no kidding they were dressed in all black..LOL! ) where cutting out a section of the pool deck and a thinner (16”x16”) column that punched through the pool deck. At least it appeared that they were cutting out a sample to remove it from the site. The area that they were removing the samples from looked to be the same basic area that you identified in your video. 2) The implosion contractor mentioned that the actual column location and sizes did not not match the plans that Surfside gave him. 3) The initial rescue/recovery videos only showed a couple of bars that stuck out of the columns into the deck (the plans showed 4). 4) All the various items that you mentioned, added planters, failed or no waterproofing, the test area left open, staining of the pavers, etc. made things a lot worse. My conclusion is that you are correct in this video. This building was thrown together fast and cheap in the early 80’s, under designed, poorly maintained and the HOA was only concerned with appearances. It’s a real shame. Very tragic!

[@minnahumble2294]

Did you notice when they cut out that portion of pool deck that they PULLED OUT THE REBAR and tossed it aside. To me that was criminal! It Made my blood boil.

[@PaulJersey]

@@minnahumble2294 I did see that. Not good!

[@helengarsed3979]

I would like to know what holds each roof up on a Tall Building like this Condo Collapse in Florida do they have BATERNS BETWEEN EACH FLOOR AS ON MY ROOF THERE WAS A BROKEN BATTERN AND THE CHAP WHO CAME OUT FOR THE ROOF HE SAID if he NOT HAD SEEN IT HE WOULD OF FELL THROUGH THE ROOF SO JUST WONDERING.LOVE your Videos and very informative Jeff

[@roubinekibinian1578]

Hi your theory of pulling the columns of the building down with the pool deck is very accurate. More so when the connection with a drop down column attached to it. Something to consider is the concrete under the building was not exposed to water . Meaning the connection was very solid unlike the concrete on the deck. The pulling forces with a solid connection would play a very big role. Someone has to calculate the load and the shear force of the deck to find out the pulling forces .

[@jeffostroff]

We already now the garage ceiling was exposed to water, our previous video on the garage last week showed videos in there that people had taken of the water leaks and stalactites and cracks and spalling.

[@mowtivatedmechanic1172]

Surprised no one is mentioning the weight of the pavers. There’s tons of weight right there.

[@roubinekibinian1578]

@@mowtivatedmechanic1172 I am sure whoever is investigating the collapse is doing the math.

[@allofyourdreams]

the pool deck should not have been connected to the building, that was very bad design from start...

[@allofyourdreams]

even even if they calculate, they need to think of that water weight that soaked into the pool deck, and also it was probably not structurally sound from the expanded rebar. If everything was sloped maybe the building would still be standing

[@catylynch7909]

As someone who has no training in architecture, or structural engineering, I very much appreciate your video explanations.

[@electrojones]

Whenever a building fails, the reason was money.

[@kineahora8736]

Pretty much true. Cheap design, poor maintenance…

[@barbaraseymour3437]

Absolutely.

[@FAB-ix9fu]

Especially if you're dealing with the "notorious Miami mob". . Miami has the most corrupted public officials in the entire country!!

[@wesleyhurd3574]

Money, in addition to one or more of the following factors: apathy, procrastintion, corruption, or incompetence.

[@kineahora8736]

@@wesleyhurd3574 corruption = money. The others are independent🤙🏻.

[@elizabethandrews4199]

Was the place of the excavation work selected because there was suspected problems. Or did the excavation work not put back caused problems?

[@gindie1]

Another KZbinr (a structural engineer) was looking at the possibility of problems with water coming up from underneath the parking garage. A lot of those columns in the garage were saturated a couple of feet at the bottom. And, there was a large part of the garage floor replaced (the video from the prospective buyer).

[@mp194801]

Thanks for the information about the slopping water drains - I just thought it may have been the cause of why there was so much water on the floor of the under-roof garage - and you showing the cracks around the drain pipes adds to my thinking. I enjoyed your analysis and can follow it clearly - it all makes sense to someone who's not a engineer minded person. Thank you for doing this time consuming research - because we the people need to know what the look-out signs are to be aware and educated. Not that I would ever live in one of those condoms but to me it's about saving peoples lives. So Be It!!!

[@rosemarywalker924]

The acid from the soil in the planter could also affected the concrete and in the first picture looking down at pool deck it a mixture of water and soil and I think the planters are compromised at the bottom .

[@jeffostroff]

the planters supposedly are waterproofed

[@rosemarywalker924]

@@jeffostroff thinks for your reply yes they are put we don't really know and if the planters are compromised around the sides some photographs show paint peeling around outside the planters at the bottom.

[@timhartherz5652]

Considering the building is right next to the ocean, i feel like the salty air would have done worse than the soil in the planters ever could have, given the damaged/uneffective waterproofing.

[@rosemarywalker924]

@@timhartherz5652 if the soil is peat which is acidic peat can hold a lots of water like peat bogs adding to the weight to the columns making the concrete like a sponge.

[@timhartherz5652]

@@rosemarywalker924 Possibly, though we have to wait until the final report to find out if this was a contributing factor. Personally i don't believe the weight of the Planters/Palms played a huge role, though i'm willing to change my mind in the face of hard evidence. The entire pooldeck was waterlogged, cracked and shoddyly patched multiple times, the planter just happened to be the first place the weight exeeded it's remaining carryload. Remember that tourist video after the first piece came down, there was water pouring into the garage, where did all of this water came from, can't just be from that one planter. The firefighter were kneedeep into water in one of the other vids, must have been several times the pools content worth of water down there, pretty sure they shut off the water supply rather quickly, can't all come from broken pipes.

[@helpyourcattodrive]

❤So many answers. I remember when this happened twenty five minutes from my childhood home and I had no clue what could have caused it … but I now I know so much more … WOW. Thank you.

[@barowt]

Make sure you get the credit for discovering that the two core samples and the shoddy repair work done last year is what brought it down..

[@jeffostroff]

I'm sure others will steal my idea and investigations

[@Suzanne1999]

@@jeffostroff 😅 Yup. I just want to take this opportunity to tell you, Jeff, how fascinating it is, you taking us on this trip. Thank you for sharing all your knowledge and taking the time to put these videos together. Outstanding! 🌟🌟🌟

[@naiduk]

I learned so much! Thank you for breaking it all the way down! And in terms and language we can all understand. Strength and light to all the families who lost loved ones. This was such an avoidable tragedy! Smh

[@ChadDidNothingWrong]

That old 80-something lady, who barely escaped......she said she ran down because a big crack was coming up her wall. What unit was she in?? B/c If her unit was above the garage entry, wouldn't it put that crack directly above the column that (Maybe) fell over in the tourist video? That could maybe (help) confirm or debunk this tourist video column theory....

[@jazzman92478]

The Nir Family was in 111. The lady you're asking about is in 611. The famous Ring Camera video is in 711.

[@gracieg7601]

I think she was on 7. Not positive. I did hear her talking about it.

[@gracieg7601]

@@jazzman92478 oh ok. I was thinking 7.

[@chetmyers7041]

@@jazzman92478 What does the Ring Camera Video show? Gotta link for it?

[@jazzman92478]

@@chetmyers7041 search KZbin. It’s widely available.

[@stevepowsinger733]

Im not sure what the photo @14:40 is. It looks like a green carpeted basketball court with six sheared off columns. In back is sidewalk path and lawn. At a higher level? I don’t get it.

[@jeffostroff]

I think it was some sort of recreational playing field on top of a garage

[@RedHotMessResell]

Whoever did my mom’s patio didn’t make it at an angle, and every time it rains a lot, the water pools and gets really close to flooding our basement. 😨

[@pettylove86]

We had a basic cement patio put in years ago and I always disliked the slant of it; I could notice it looking at the table. I now am thankful - no water pooling or flooding.

[@RedHotMessResell]

@@pettylove86 yes exactly. I mean I guess sometimes contractors will slant it too much, because I’ve had some bad contractors on my recent reno investment, but yes exactly. Keeps the patio lasting longer too. Mom’s is cracked and falling apart. We had to get rid of the firepit benches and the firepit is pretty much just a hole in the ground now with the rocks crumbling around it.

[@brians4537]

At 2:17 you show a section of the structural repair drawing. Could you speak about the "CONCRETE SLAB SOFFIT REPAIR" and the "CONCRETE CORBEL REPAIR"? Could these be related to the fallen concrete seen through the parking entrance gate?

[@nancyswan2056]

I read in another video the palm trees were removed because the condo homeowners could not see the ocean view they were paying for. So wanted their removal.

[@alaskajax2]

Thank you for using larger pointers in this video. Excellent presentation.

[@billj5645]

The 16x16 column is carrying load from every floor of the tower, the 12x16 is only carrying load from the pol deck. Also note that the 16x16 has 8#11 reinforcing bars, the 12x16 only has 4#7. The 16x16 has 4 times as much reinforcing steel as the 12x16. The beams around that area are there primarily to be transitions between different slab levels. If you study the drawings for that area you can see that there are a lot of different slab elevations involved. It is not possible from the crude video to tell how the concrete framing was constructed. Normally all of the beams would be poured over the columns, even the beams that are narrower than the columns. Without paint you should be able to see a cold joint there. If they did not do this then they did not build it correctly per standard practice of every contractor I've ever seen. However if they had built it incorrectly by pocketing the beam into the side of the columns then the beam A would possibly not have as much ability to pull as much on the side of the column. Yes the palm trees might be heavy but the outside pool deck should have been designed for enough live load to allow for the trees.

[@tubester4567]

Right. I think its more likely there are bigger problems like poor quality concrete, made worse from salt water intrusion around the foundations. One of the investigators said the drill samples were very soft and easy to drill.

[@punker4Real]

did it account for the roots of the plant? roots can tear apart concrete esp if there is plenty of water around

[@jeffostroff]

What about heavy equipment used to position palm trees? Id out that pedestrian pool deck is designed to have big heavy forklifts on them, with tall palm trees weight 1000 pounds each. Also if they had an isolation seam from the pool deck to the building, maybe it would not have collapsed the builfding.

[@billj5645]

@@jeffostroff I wonder if the palm trees are significantly heavier than that, 1000# would be insignificant, the concrete deck wouldn't feel it. Heavy equipment is a relative term, contractors always want to use heavier equipment than engineers think are acceptable. I think outside decks like that should be designed for 100 psf live load which would allow use of a piece of equipment with maximum total weight of 10,000 to 15,000 pounds.

[@billj5645]

@@jeffostroff The pool deck seems to have several deficiencies. It has not been shown how the pool deck did affect the building but having them as separate structures would have of course eliminated the influence. However this is almost never done for other reasons. Despite the water problems of this building, having an actual expansion joint between building and pool deck would have been much worse. And the additional columns in the basement have an affect on the parking layout and how many cars they can fit in.

[@feledorjones2648]

You Are on Point. I like your Expertise, the music playing in the background. It's relaxing how you lay your theory out, Awesome.

[@Kimbyrleigha]

I was so sad! The video was gone while I was watching. So glad it’s back

[@nk361]

Me too, but I got close to the ending of it and it was spazzing out like crazy and not showing what he wanted to show. I think that was the reason for the re-upload

[@lilacscentedfushias1852]

It’s so annoying when that happens! Especially if it’s the end of something or the next part.

[@kev03103]

The sister bldg is in much better shape. I've heard that this building had a lot of cheap skates living there. The kept putting things off. Finally they realized that they better get going but WHAAMO, too late.

[@Deeniesweden]

@@kev03103 I would definitely moved out of the sister building if I had an apartment there. 😬

[@andresmonterrey887]

Water flows through the path of least resistance

[@littlevwbus]

there is a lot concrete work going on by the column collapse 2:30 ,sheet 42 i think, pool deck is 7 to 18 inches lower than inside the buildings 1st floor ending all at 18 lower 15:00 shows pool deck pulled down with the beam still up, that beam looks to me to be part of the stepping down from 7 in drop to 18 in drop making it part of the deck. there is two H structures between 78 and 27 tying all the pool decking together the H structures is where the pool deck steps down. so with that said if you hinge down the pool deck, that is 18in lower than the 1st floor, all the compression force will go into the side if the column under the 1st floor lever, undercutting the 16X16in column that holds up the outside wall. and now that the column shape being turned into the letter C, the weight of the building just smashed the C "column" down bringing down the outside wall...

[@txdomino]

A possible reason to why the columns are smaller on that side of the building is because of the parking. Typically parking spaces are about 8 to 9 feet wide. That gives you enough room to maneuver the car into the space without hitting a column and then enough space on either side to open the doors. Therefore the columns would have to be small enough for you to maneuver into the space. If the columns get thicker then you wouldn't be able to comfortably maneuver into the space because the space is narrow. That's probably what they did here. The only way to make this work is if those parking spaces were a lot wider to accommodate a thicker column. Doing this would significantly change the design and number of parking spaces and the alignment of the column grid in regards to the rest of the building.

[@aaallright]

The standing part of the building was built stronger because of stronger wind effects on that building. On the 24x24 colums are additional vertical beams between ground and upper floor. Maybe that was the reason for the smaller columns on the collapsed part

[@eddiejaze8309]

On another video, it seems they just opened more and more parking spaces "above ground". The cars that look perfect, until you notice , Jeff points it out, they fell a full story. It's possible the engineers didnt expect /plan cars to be parked there. If each car weighs a ton, and management, not engineers think, well let's just start parking cars here. Same as the planters, then there are overzealous gardeners/landscapers, it's not there job or expert6to worry about spalling, and as sad as it is, there is that one person's account of telling security in the lobby "hit the fire alarm", he isn't an engineer. If "my fire alarm panel isn't showing anything, " I might hesitate too. Not blaming all these workers, but apathy sucks. God bless those souls

[@Robert08010]

@17:32, I would have interpreted those as the shadows of pipes that are out of view. I think if those were compressions marks, there would have to be big ceiling cracks around that column, I would suspect they would have to be big enough to be visible. But if you're right, that could be a real smoking gun. I'm glad you brought up that bowed beam. I couldn't say for sure that is wasn't simply the effect of a wide angle lens, but honestly, I thought it looked bowed too.