One clip, posted by X, formerly Twitter, user Tyler Anderson, shows the plane in the far distance in the night sky before it collides with the helicopter. In the clip, aviation control clears the flight to land, advising PAT25 helicopter to watch out for traffic.

"We are switching from a rescue operation to a recovery operation," Fire and EMS Chief John Donnelly said during a press conference Thursday morning.

A pilot's theory about the cause of the crash between an American Airlines jet and a military helicopter has quickly gone viral online.

Three soldiers were on the helicopter. The collision happened around 9 p.m. when the PSA Airlines Bombardier CRJ700 regional jet was on approach to the airport. Map of the area around Ronald Reagan Washington National Airport and the layout of Runway 33,