A gas leak is suspected to have caused an explosion Monday that leveled multiple buildings and injured at least seven people in Rio de Janeiro, Brazil, UPI reported. The BBC reports the blast, which witnesses claimed to have heard 4 miles away, occurred in the Sao Cristovao neighborhood, damaging about 40 homes and businesses. "The roof caved in and my 21-year-old son managed to shield my 18-year-old daughter with his body," local resident Marlene Sangy Aires told O Globo newspaper. "We were trapped in the rubble and used the light of our mobile phones to signal to the rescue workers. They found us and pulled us out." Brazilian media reports one of the injured included a 9-year-old girl who was trapped under debris for at least three hours. Rescue workers are sifting through the rubble but have not reported any dead. Officials say a gas leak at a local business may have caused the explosion.