daf bit: Bava Kama 30
The talmud moves on from damages caused by animals to damages caused by
people unintentionally. The mishna says: if a man pours out water into
public ground and somebody is injured as a result, he is liable. And
similarly if he dumps thorns or broken glass and someone is injured, he is
liable. A second mishna adds: if a man places straw and stubble into the
public ground to be turned into manure and damage results to some other
person, he is liable and whoever seizes them first gains title.
R' Shimon ben Gamliel generalizes this: whoever creates any nuisance on
public ground causing damage is liable to compensate, and whoever seizes the
items first gains title to them. (30a)