The Black Hawk helicopter that crashed into an American Airlines flight was alerted to the plane’s presence by air control twice.

Air traffic controllers twice alerted the crew of a U.S. Army helicopter to the presence of an inbound American Airlines jet, with the first warning issued two minutes before the aircraft collided Wednesday night near Reagan National Airport, radio transmissions show.

Video recorded by bystanders shows the harrowing moment when the 2 aircraft crashed into one another, causing an explosion over the nation's capital.