[If] a ground floor and an upper story belonging to two [different people] collapsed, the two of them divide the wood, the stones, and the earth; and they determine which stones are likely to have been broken. If one of them recognized some of his stones, he takes them, and they are counted for him in the reckoning.

[If] a ground floor and an upper story belonged to two [people], [and] the upper story partially fell in, but the owner of the ground floor does not wish to make repairs, the occupant of the upper story may go and live downstairs, until he repairs the upper story for him. R’ Yose says: The downstairs one supplies the ceiling, and the upstairs one the plaster.