Hundreds of flights have been canceled, and New York’s LaGuardia Airport (LGA) is expected to remain closed until at least Monday afternoon after an overnight ground collision involving an Air Canada regional jet and a vehicle.

Shortly after 11:40 p.m. Sunday, an Air Canada CRJ-900 inbound from Montreal-Trudeau International Airport (YUL) collided with an airport fire truck that was responding to another incident, the Federal Aviation Administration said.

The aircraft had just landed and was taxiing at the time.

Seventy-two passengers and four crew members were on board the plane at the time, according to regional carrier Jazz Aviation, which operated the flight as Air Canada 8646.

At a news conference early Monday morning, the Port Authority of New York and New Jersey confirmed both pilots were killed, and dozens of passengers sustained injuries.

The National Transportation Safety Board arrived at the airport early Monday and is leading the investigation, which is protocol after an aviation incident like this.

Meanwhile, LaGuardia — one of the busiest airline hubs in the Northeast — was expected to remain shut down for hours Monday in the aftermath of the collision.

In a post just after 5 a.m. Monday, LGA said it expected flights to be halted until at least 2 p.m.

By 7:15 a.m., more than half of all planned Monday departures from the airport had already been canceled, data from FlightAware showed.

It’s likely that number will grow as the day progresses.

Some airlines began to issue travel waivers to give travelers with flights booked Monday added flexibility to change their itineraries.

American Airlines, which operates a hub out of LaGuardia’s Terminal B, was waiving change fees and granting added flexibility for passengers booked on flights to, from or through the airport Monday.

Meanwhile, in a statement Monday, Air Canada urged family and friends of passengers on Air Canada Express Flight 8646 to contact the airline at 800-961-7099.

“We are deeply saddened by the loss of two Jazz employees, and our deepest condolences go out to the entire Jazz community and their families,” the carrier said.

This is a developing story. Check back for further updates.