In the deadliest U.S. major commercial aviation incident in 16 years, there were no survivors in a collision between a commercial aircraft and an Army helicopter by Ronald Reagan National Airport near Washington D.

After American Airlines Flight 5342 and a U.S. Army helicopter collided mid-air, officials shared insight into the respective pilots’ communication with air traffic control.

Air traffic controller audio TIME retrieved from LiveATC.net revealed what happened moments before the collision. The tower had cleared the plane for landing on Runway 33, but just seconds before the crash, an air traffic operator asked the helicopter—with radio call sign PAT 25—if the commercial jet—referred to as the CRJ—was in sight.