New York: A horrific runway collision at LaGuardia Airport (LGA) has claimed the lives of the pilot and co-pilot of an Air Canada Express flight late Sunday night. The aircraft, arriving from Montreal, struck a Port Authority fire engine during its landing roll, triggering a mass-casualty response and a total shutdown of the major New York hub.

The incident occurred around 11:40 pm local time on Runway 4. Viral social media footage shows the nose of the commuter jet completely crushed and tilted upward as passengers were evacuated via emergency slides.

Four firefighters from the Port Authority Police Department (PAPD) sustained life-threatening injuries.

Approximately 100 passengers were on board, including a large group of Orthodox Jews returning to the New York area. Their conditions are currently being evaluated by medical teams.

The Federal Aviation Administration (FAA) moved swiftly to issue a comprehensive ground stop for all flights. The regulator cited an "emergency" and warned of a high probability of an extended closure.

All arriving flights have been diverted or forced to return to their origin.

The collision is being treated as a major aviation accident. Heavy rescue equipment and dozens of ambulances were seen swarming Runway 4 shortly after the impact.