A commercial building in Brazil's biggest city has collapsed and officials said at least 15 people are trapped in the rubble, AP reported. Firefighters say they've pulled three survivors from the collapse in Sao Paulo. It's not yet clear what caused the building to fall. About 60 firefighters were carefully searching the rubble, using dogs to help locate victims. Nearby vehicles were covered with chunks of concrete let loose as the building fell. The building was either being built or was under repair. It was two stories high. Firefighter Marcos Palumbo tells the Globo TV network that "right now the work is slow, very cautious, because to pull people from the rubble we need a lot of technique and patience."
