At 8:47 p.m., an air traffic controller is heard hailing the helicopter.
"PAT25, do you have a CRJ in sight? PAT25, pass behind the CRJ," an air traffic controller says.
Seconds later, another aircraft called in to air traffic control, saying, "Tower, did you see that?" - apparently referring to the crash. An air traffic controller then redirected planes heading to runway 33 at Reagan Washington National Airport to go around.
"Crash, crash, crash, this is an alert three," one of the air traffic controllers can be heard saying in the audio from around the time of the crash.
"I don't know if you caught earlier what happened, but there was a collision on the approach into 33. We're going to be shutting down operations for the indefinite future," another controller remarked.