The National Transportation Safety Board is leading the investigation. White House Press Secretary Karoline Leavitt confirmed that a military helicopter collided with a regional jet near Reagan National Airport outside Washington, D.C.

Sixty passengers and four crew members from the plane and three Black Hawk helicopter personnel are feared dead as a recovery mission is underway.

All 64 people aboard an American Airlines jet that collided with an Army helicopter were feared dead in what was likely to be the worst U.S. aviation disaster in almost a quarter century, officials said Thursday.