Eyewitnesses have described the moment Air Canada flight AC8646 crashed into a fire truck on the runway of New York's LaGuardia airport, killing two pilots and injuring dozens of others.

"We were literally like 100 metres away," says 23-year-old Leo Medina, who was onboard another plane on the tarmac when the crash happened. "It was like the plane got cut in half."

He told the BBC he then had to return to the gate and had been waiting in the airport for more than 12 hours, sleeping on the floor on a bed of jackets.

Passenger Rebecca Liquori - who was on the plane arriving from Montreal that crashed - told News12 Long Island there was a loud "boom" just after it landed.

"As we were descending, we hit a lot of turbulence," she said. "Then we landed very roughly… Everyone felt it. It was like the plane jolted and you heard the pilot try to brake trying to prevent the collision."

"As you heard the brake, a couple seconds later it was just a very loud boom," she said. "Everybody jolted out of their seats."

The crash - which happened at 23:40 local time on Sunday (03:40 GMT on Monday) - saw two pilots killed, and 41 people others taken to hospital, some with serious injuries.

In audio from the air traffic control tower at LaGuardia, a staff member can be heard saying: "'Truck One, stop, stop, stop!" in the seconds before the crash.

The truck had been called out minutes earlier to a separate incident on board another plane which had "reported an issue with odour", according to Port Authority executive director Kathryn Garcia.

Liquori described passengers helping each other slide down a wing to get out.

"I'm just happy to be alive," she said. "I would have never pictured a one-hour flight that I've done countless times … ending like this."

Passenger Jack Cabot - who was also on the plane that crashed - told CNN there were scenes of chaos.

"We went down for a regular landing," he said. "We immediately hit something and it was just chaos from there … Everybody was hunkered down and everybody was screaming."

LaGuardia airport - one of the busiest in the US - has been closed since the crash happened, with hundreds of flights delayed or cancelled.

One traveller - 26-year-old Katie Rojas - whose flight to Chicago was on the runway and ready to depart when the crash happened said: "It's scary. You never know if it could have been one of us."