Air traffic controller audio obtained by CNN from LiveATC.net captures the moment the air traffic control operators ask the helicopter if the commercial flight operated by PSA Airlines is in sight.

An air traffic controller said, “PAT 2-5 do you have the CRJ in sight?”

The controller then said, “PAT 2-5 pass behind the CRJ.”

Additional air traffic control audio shortly before the collision captures the helicopter pilot saying, “PAT 2-5 has aircraft in sight, request visual separation.”

Less than 13 seconds later, the audio then captured audible gasps, including a loud “oooh” in the background apparently from the tower, at the moment of the crash.

The tower then alerted another pilot of what has taken place.

“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. Highly suggest you guys coordinate with the company. Let me know what you want to do,” the controller says, referencing runway 33.

The audio also revealed that another pilot had seen the incident and confirmed with an air traffic controller.

Another pilot could be heard saying, “Yeah, we were on short final, and we saw flares from the opposite side of the Potomac.”

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

A number of other aircraft made plans to divert to other airports following the incident as flights at DCA were halted.