Necessity as a Defense in Tort Law

Necessity can be a defence in tort law, if it can be proven that it was absolutely necessary to commit an act, that caused some injury or harm to the plaintiff.
The necessity can be a private necessity or a public necessity - and normally public necessity is a much stronger defence.
For example, a house was on fire, to prevent the fire from spreading across to the next house, the neighbour demolished a part of the burning house.
This can be a private necessity - to prevent harm to the neighbours own house.
On the other hand, if there was risk of the fire spreading to multiple houses across the neighbourhood, then the demolition of a part of the burning house would be a public necessity.
For the defence of necessity to work, it should meet certain essential criteria.
There must be some imminent - that is a real and immediate danger - which makes the act necessary.
The person committing the act must have a reasonable belief that the action is required to avert the danger.
There was no other practical and reasonable alternative.
There should be proportionality - i.e. the damage done by the tort should be less than the potential damage that would have happened if the act was not done.
And, necessity is a defence that protects acts done when there is an immediate danger - if there is no immediate danger - or the danger has passed, then there is no necessity.
In the Cope v. Sharpe case, a fire broke out in the plaintiff’s land. The defendant trespassed into the neighbour’s land to take some action to prevent the fire from spreading into the adjacent fields.
The defendant’s actions caused some damage, to the plaintiff’s fields, so he approached the court.
The court ruled that the defendant’s actions were justified, because they were necessary, to prevent the fire from spreading.