Palermo, December 18 - Four people are dead after two buildings collapsed in the Sicilian city of Palermo overnight. Firefighters have found the bodies of a married couple in their 80s, a 54-year-old man and his 74-year-old aunt in Via Bagolino, a street in the area of Palermo's shipyards. The number of victims would have been higher if the firefighters had not ordered an immediate evacuation of the buildings after being called when residents heard strange noises and noticed cracks in walls were getting bigger. "Today the noises worried us more than usual and we called the fire brigade, who immediately had us evacuate," said one of the survivors, Giuseppina Ferrara. "A few minutes later it all came down". Seven people were injured, including three children. Rescuers managed to pull a small dog out of the rubble alive. Palermo Mayor Leoluca Orlando rushed to the scene of the disaster to help oversee operations. Twenty people were made homeless by the collapses. Palermo prosecutors have opened an investigation. City documents showed that some floors of the buildings had been constructed illegally without planning permission. The local branch of Environmental association Legambiente said efforts to combat illegal building needed to be stepped up. "The lack of control and of renovation of historic buildings, especially in the suburbs, is putting our districts and citizens' lives at risk," Legambiente said in a statement. "It is necessary to renew this area (and save it) from widespread illegal building... "Much of our city is compromised by illegal building".