A late-night collision Sunday between a passenger jet and an emergency response truck at LaGuardia Airport left two crew members dead and dozens injured, prompting the airport’s closure and the launch of a federal investigation.

The aircraft, operating as Air Canada Express Flight 8646 from Montreal and flown by Jazz Aviation, struck a Port Authority Aircraft Rescue and Firefighting vehicle at 11:47 p.m. ET, according to the airline and officials. Two sources familiar with the investigation said the fatalities were the pilot and co-pilot. The New York City medical examiner is overseeing the case, NBC reported.

Initial information from a senior official with knowledge of the investigation indicates that more than a dozen passengers sustained injuries of varying severity. Some of the injured were transported to Elmhurst and Queens Presbyterian hospitals, the source said.

Two additional people were reported injured in the crash, though authorities did not provide further details on their conditions.

Passenger counts differed between sources. Officials said there were 76 passengers and four crew members on board, while Jazz Aviation said its preliminary manifest listed 72 passengers and four crew members and cautioned that those figures remain subject to confirmation. The airline identified the aircraft as a CRJ-900.

According to a Port Authority spokesperson, the emergency vehicle involved had been dispatched to another incident at the time of the collision. No further details were provided about that call.

“Emergency response protocols were immediately activated,” the spokesperson said. “The Port Authority Police Department is on scene along with the agency’s chairman and executive director.”

LaGuardia Airport was shut down around midnight to support emergency operations and investigative work. Officials said it is expected to reopen later Monday.

The National Transportation Safety Board said it is deploying a go team to examine the incident, with investigators expected to arrive Monday. The Port Authority Police Department said additional updates will be released as the investigation progresses.