Bava Metzia 116 - The Ground and the Upper Floor of a House

If two people lived in a two-story house, such as two brothers who inherited their father's house, one taking the ground floor and the other the upper story, and the building collapsed, how do we allocate the debris? They divide the wood, the stones, and the earth (used as cement) in proportion to the heights of their respective properties.

To allocate the whole and the broken stones, we determine how each wall collapsed. If it collapsed directly downwards, presumably the lower stones broke, and the rest of the wall fell upon them, so the whole stones are allotted to the owner of the upper story. If the wall was knocked over to the side, presumably the upper stones broke, and the owner of the ground floor gets the whole ones.