Air traffic controllers warned the pilots of a US Army helicopter circling Washington DC moments before it collided with an American Airlines commercial jet.
Audio obtained by CNN captured the moment operators asked the Black Hawk helicopter if it could see the plane, which was operated by PSA Airlines.
"PAT 2-5, do you have the CRJ in sight?" the air traffic controller asked the helicopter less than 30 seconds before the crash.
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"PAT 2-5, pass behind the CRJ," the controller added.
The audio recorded then gasps from those inside the helicopter at the moment of impact.
The controllers then alerted another pilot of the crash, which the recording captured.
"I don't know if you caught earlier what happened, but there was a collision on the approach end of 3-3. We are going to be shutting down operations for the indefinite future if you want to go back to the gate," the controller said.
"Highly suggest you guys coordinate with the company. Let me know what you want to do."
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One pilot responded and said it saw "flares from the opposite side of the Potomac (River)".
"Tower did you see that?" another pilot is heard in audio sent to the tower following the crash.
"Apparently both aircraft involved are in the river, a search and rescue will be ongoing," the controller later said.
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Several minutes before landing, air traffic controllers also asked the arriving commercial jet if it could land on the shorter Runway 33 at Reagan National, Associated Press reports.
The pilots confirmed they were able and controllers had cleared the plane to land on Runway 33 before the crash.
Flight tracking sites reveal the plane adjusting approach to the new runway before impact.
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AP reports the plane's radio transponder stopped transmitting roughly when it was flying over the river.
US President Donald Trump, who has been briefed on the crash, has taken to his platform Truth Social to speak about the incident.
The president said it was a "clear night" and asked why the helicopter did not see the approaching plane.
"Why didn't the control tower tell the helicopter what to do instead of asking if they saw the plane," Trump wrote.
"This is a bad situation that looks like it should have been prevented. NOT GOOD!!!"
A law enforcement source told CNN the plane is in pieces in the water and the helicopter is in the water nearby.
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