Both pilots in an Air Canada Express jet were killed when it collided with a fire engine while landing at New York's LaGuardia airport late on Sunday.
Dozens of people were injured dozens and the airport remained closed on Monday morning, authorities said. Flights were expected to resume in the afternoon.
An Air Canada flight attendant was violently thrown from the plane and was still strapped into her jump seat when she was found, the New York Post reported, citing sources.
The Air Canada Express CRJ-900 plane, operated by its regional partner Jazz Aviation, was carrying 72 passengers and four crew and had left Montreal, said Jazz, which is owned by Chorus Aviation.
Jazz and the Port Authority of New York and New Jersey confirmed that the pilot and first officer were killed.
The crash comes as US aviation faces chronic shortages of air-traffic controllers and a separate shortfall of airport security screeners because of a partial government shutdown that has led to delays, long security queues and heightened safety concerns across airports nationwide.
A separate 35-minute ground stop at nearby Newark Liberty International on Monday morning added to delays after air-traffic controllers evacuated their tower because of a burning smell from an lift, the Federal Aviation Administration said.
“Today is an incredibly difficult day for our airline, our employees, and most importantly, the families and loved ones of those affected by the accident involving flight 8646,” Jazz president Doug Clarke said.
Kathryn Garcia, executive director of the Port Authority, said 32 of the 41 injured had been released, while nine remained in hospital with “serious injuries”.
US Transportation Secretary Sean Duffy said at least two Port Authority firefighters sustained serious injuries.
Aviation safety experts said investigators would look at air traffic control staffing levels and the actions of both the controller and fire engine crew.
Ms Garcia said the engine was responding to a separate United Airlines aircraft that had “reported an issue with odour”.
Minutes earlier, air traffic control audio from LiveATC.net indicated that a United flight had declared an emergency because of a smell on-board. Controllers advised the crew that firefighting vehicles were already on site.
A later transmission captured a fire engine being cleared to cross Runway 4 at taxiway Delta, where the collision occurred.
Moments later, according to the ATC audio, a controller can be heard saying: “Stop, stop, stop, Truck 1 stop, Truck 1, stop,” according to Reuters.
The aircraft struck the fire vehicle at about 39kph, according to flight-tracking website Flightradar24.
Photos taken by Reuters after the accident showed damage to the nose of the plane, which was tilted upwards.
Two unnamed passengers told ABC affiliate WABC of the shock on board, with one describing a friend suffering a broken nose and travellers hitting their heads on the seats ahead.
