Authorities say two vehicles collided Saturday night in South Los Angeles and burst into flames. Officials say an infant, a child and an adult all were pronounced dead at the scene. Three other people including a child were taken to area hospitals in critical condition. Cellphone videos show bystanders running around the vehicles trying to help the screaming victims, but heavy flames kept them from reaching the people trapped inside. No other information was immediately available. The cause of the crash remains under investigation.