In Re An Arbitration between Polemis & Furness,withy &Co.(1921)–Case Summary 

Facts:

Defendants chartered a ship.The cargo to be carried by them,included a quantity of Benzene and Petrol in tins. Due to leakage in those tins, some of their contents collected in the hold of the ship. Owing to the negligence of the defendant’s servant,  a plank fell into the hold , a spark was caused & consequently the ship was totally destroyed by fire.

Issue:

1. Whether defendant can be held tortiously liable for the outcome of events entirely caused by actions which could not have been forseen?
2. Was damage a direct consequence?

Ratio:

1. To determine whether an act is negligent, it is relevant to determine whether any reasonable  person would foresee that the act would cause damage; if he would not, the act is not negligent. But if the act would or might probably cause damage, the fact that the damage it in  fact causes is not the exact kind of damage one would expect is immaterial,  So  long as the  damage is in fact directly traceable to the negligent act, and not due to the operation of  independent causes having no connection with the negligent act, except that they could not avoid its result.
2. Once the act is negligent, the fact that it’s exact operation was not forseen is immaterial.

Decision:

In the present case, it was negligent in discharging cargo to  knock down the planks of the temporary staging, for they might easily cause some damage  either to the workmen, or cargo, or the ship. The fact that they did directly produce an  unexpected result, a spark in an atmosphere of petrol vapour which caused a fire, does not  relieve the person who was negligent from the damage which his negligent act direclty caused.

For Reference:

https://www.ijlpa.com/_files/ugd/5f2b28_4d96f38e6e5741df8ed2201f45f2f2e1.pdf?index=true