Investigators have already recovered the cockpit voice recorder and flight data recorder of the American Airlines plane that collided with an Army helicopter near Ronald Reagan National Airport.

Investigators have recovered the flight recorders—also known as black boxes—from both the commercial jet and the military helicopter involved in the mid-air collision near Reagan National Airport in Washington,

Rescue crews will return to the Potomac River on Friday morning as they continue searching for victims of Wednesday night’s deadly midair collision.