Updated

Two adjacent apartment buildings collapsed in Palermo, Sicily, killing four residents and injuring 12, and prosecutors are investigating allegations that a top floor was illegally added to one of the structures, Italian news reports said Tuesday.

News agency LaPresse said residents called firefighters Monday evening after noticing cracks in the walls of one of the buildings. While firefighters were evacuating residents, the two structures collapsed, one after the other.

A half dozen families escaped before the tragedy reduced the buildings to heaps of cement, furniture and home supplies. Rescuers pulled four bodies from the rubble.

The ANSA news agency quoted resident Giuseppina Ferrara as saying a fourth floor had been added to one of the buildings last year, destabilizing it. Sky TG24 TV reported that prosecutors have begun an investigation to see if that floor's weight caused the collapse.

More On This...