Chilling air traffic control audio has emerged from the moments before and after an American Airlines plane crashed into a military helicopter.

At least 18 passengers have been rescued from the cold waters of the Potomac River after Flight 5342 collided with a Black Hawk Sikorsky H-60 helicopter during an attempted landing in Washington DC.

The airline has confirmed 60 passengers and four crew were on board the Bombardier CRJ700 at the time. Three people were traveling on the chopper. 

A law enforcement source told CNN that there are confirmed fatalities but a number is yet to be confirmed. 

In the aftermath of the tragedy, Air Traffic Control (ATC) audio emerged from around the time of the incident. 

In the nearly minute-and-a-half recording, ATC operators can be heard asking the helicopter if the commercial flight is in sight.

Through muffled audio, more commands and confirmations are made between ATC operators.

One air traffic controller said: ‘PAT 2-5 do you have the CRJ in sight?’

Seconds later, the controller spoke again, requesting: ‘Pat 2-5 pass behind the CRJ.’

A haunting, audible gasp can be heard at the moment of the crash from the tower, according to CNN. 

The terrifying collision prompted the tower to alert another pilot of what had just taken place.

CNN reported that the air traffic controller stated, ‘I don’t know if you caught earlier what happened, but there was a collision on the approach end 3-3. We are going to be shutting down operations for the indefinite future if you want to go back to the gate.’

‘Highly suggest you guys coordinate with the company,’ the audio continued. ‘Let me know what you want to do.’

The distressing audio also disclosed that another pilot, who witnessed the crash firsthand, confirmed the incident with an air traffic controller, as per CNN’s report.

The pilot who witnessed the devastating collision said: ‘Yeah, we were on short final and we saw flares from the opposite side of the Potomac.’

According to NBC, a controller detailed what they saw in the moments after the incident, which was also captured in the audio. 

The operator said: ‘It was probably out in the middle of the river. Um, I just saw a fireball and then it was just gone. I haven’t seen anything since they hit the river.’ 

An approach controller later said: ‘Apparently both aircraft involved are in the river, a search and rescue will be ongoing.’ 

The horrific accident prompted a large-scale search and rescue operation over the river as helicopters, boats and police searched the water and ground.

Roy Best, a federal employee, told CNN that he was on the rooftop of his building, which is located next to the airport, when the collision happened.

‘It was just a loud noise,’ he said. ‘So I turned to the side, and I saw a big spark. And then just something falling. Because it was kind of dark. Couldn’t really tell what it was. I didn’t know if it was a firecracker or what.’

The US Army Black Hawk that collided with the passenger plane was on a training flight at the time of the crash, Heather Chairez, the Joint Task Force-National Capital Region media chief, told CNN. The helicopter had a crew of three on board.

Another source told the outlet that the plane is in the river, in pieces, with the helicopter also in the water nearby. 

NBC Chief Meteorologist Doug Krammerer said that at the time if the wreck, the water temperature was about 37 degrees Fahrenheit.

At that temperature, according to Krammerer, someone in that water only has around 15 to 20 minutes before they start suffering from hypothermia.