An American Airlines regional jet collided with a U.S. Army Black Hawk helicopter on Jan. 29. Both aircraft plunged into the Potomac River near Reagan Airport.

The U.S. Army helicopter that collided with an passenger jet near Washington, D.C., had an advanced surveillance system turned off.

The Army Corps said it is first salvaging the jet — which still is believed to have bodies in it — and afterward, it will recover the fallen Black Hawk.