The collision occurred in airspace that is difficult to navigate. Flight data, video and air traffic control audio show how the tragedy unfolded.

Officials say no survivors after a passenger jet crashed with an Army helicopter on approach to a Washington, D.C., airport. Here's what we know.

An American Airlines regional passenger jet and a U.S. Army Black Hawk helicopter collided midair and crashed into the Potomac River near Reagan Washington National Airport on Wednesday night.