New Zealander captures moment two US Blackhawk helicopters crash on Utah ski field

Two American Blackhawk helicopters have crashed on an American skifield. 

It was all captured on camera by a Kiwi, who waited hours to learn if it was deadly or not. 

The two helicopters were training high above the Utah snow until they disappeared in a freak accident.

"They crashed!! They f**king crashed," a spectator said. "Oh no!" 

Watching from a chairlift, Kiwi Billy Halloran witnessed the crash.

"I heard the big bang, the rotors went flying," Halloran says.

The snowboarder told Newshub that chances of survival looked unlikely.

"Initially [I] just thought worst-case scenario," he said.

"Saw a bunch of people run over to the helicopter and then ran away, didn't look like anyone came out of the helicopter and thought perhaps some passed away. That was scary."

The helicopters were flying for the US military, undertaking routine mountain training. 

"As they landed the snow kicked up and the aircraft probably lost sight of the ground," Utah National Guard spokesman Jared Jones said.

Investigations will confirm what went wrong, but it's believed a blade fell off one helicopter then struck the other. 

But miraculously, none of the crew were hurt.

"We were certainly not prepared to see anybody die yesterday," Halloran said.

The skiers were lucky too, as the incident occurred just metres away from a ski resort near Salt Lake City. 

"It looked pretty sketchy from the start," Halloran says. 

One chair lift ride he won't ever forget.