The flight data recorder and cockpit voice recorder, known as the black boxes, may offer clues about what went wrong before the crash.

A passenger plane carrying 64 people crashed into an Army Blackhawk helicopter over the Potomac River last night, bursting into flames.

Air traffic controllers asked Flight 5342 to switch runways when coming in to land. Black box recordings from the jet and the military helicopter it collided with will help reveal whether this contributed to the accident.