WASHINGTON, Jan 30 (Reuters) - Air traffic control audio

recorded the final moments before and after the crash of an

American Airlines ( AAL ) regional passenger jet and a U.S. Army Black

Hawk helicopter after a midair collision in Washington on

Wednesday night.

Audio from LiveATC.net, a respected source for in-flight

recording, captured the final communications between the three

crew members of the helicopter - call sign PAT25 - before it

collided with the CRJ700 Bombardier jet carrying 64 passengers

and crew.

"PAT25, do you have a CRJ in sight? PAT25, pass behind the

CRJ," an air traffic controller said at 8.47 p.m. (ET) on

Wednesday (01:47 GMT on Thursday).

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.

The explosion in midair occurred over the frigid Potomac

River near the airport.

"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.

"Both the helicopter and the plane crashed in the river," a

third air traffic controller can be heard saying.

"It was probably out in the middle of the river," the

controller said. "I just saw a fireball and then it was just

gone. I haven't seen anything since they hit the river. But it

was a CRJ and a helicopter that hit."

The crash was caught on a webcam at the John F. Kennedy

Center for the Performing Arts in Washington. The clip shows the

aircraft exploding in flames and plummeting to earth after it is

struck by the helicopter.