[If] one leaves a jug in a public domain, and someone else comes along and stumbles over it and breaks it, he is exempt. If he is injured by it, the owner of the jug is liable for his injury.  [If] one's jug broke in a public domain, and someone slipped on the water or was hurt by the shards, he is liable. R' Yehudah says: If he intended, he is liable; if he did not intend, he is exempt.