A medical jet carrying a young girl, her mother and four crew members crashed into a busy residential area of northeast Philadelphia, erupting in a fireball and killing everyone on board.The Learjet 55 aircraft plunged from the sky moments after taking off from Northeast Philadelphia Airport just before 6:10 p.

Among the people on board was a child who had come to the U.S. for "life-saving treatment" and was going back home, a spokesperson for Jet Rescue Air Ambulance said.