These are the ones who are exiled: One who kills a person inadvertently. [If] he was pushing out with a roller, and it fell upon him and killed him; [or if] he was letting down a cask, and it fell upon him and killed him; [or if] he was descending a ladder, and he fell upon him and killed him —- he is exiled. But if he was drawing back the roller, and it fell upon him and killed him; [or if] he was hoisting up the cask and the rope broke, and it fell upon him and killed him; [or if] he was ascending the ladder, and he fell upon him and killed him —- he is not exiled. This is the rule: For [any death which occurs] in the course of descent, he is exiled; but for [one which occurs] not in the course of descent, he is not exiled.  Should the iron fly off its handle and kill —- Rabbi says: He is not exiled; but the Sages say: He is exiled. From the tree that is being chopped —- Rabbi says: He is exiled; but the Sages say: He is not exiled.