[dad911]

SS - I would document everything asap. Take plenty of pics, I would probably have an engineer/architect inspect.

Agree, from age likely balloon framed. Which means the walls are stressed and damaged, even below the 2nd floor level. Buckled flooring could indicate the floor joists have shifted/moved, whole structure could now be racked. (just like the roof/floor buckling in a car wreck) Fasteners have loosened, nails pulled/wood split.

Wood that was stressed needs to be replaced, and enough siding/sheathing/plaster removed to inspect for hidden damage.

From the scenario you described, operator put the whole pallet down on the roof. I'm not surprised roof structure failed, they basically put 4000# on 2 rafters.

Stressful, but fortunately no one was in the house, you are between tenants, and nobody got hurt.