Palermo, December 18 - Three people are dead and a woman is missing after two buildings collapsed in the Sicilian city of Palermo overnight. Firefighters have found the bodies of a married couple in their 80s and a 54-year-old man who is related to them in Via Bagolino, a street in the area of Palermo's shipyards. They are digging in the rubble to try to find another woman aged 74. 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.