A firefighter aboard a truck that collided with an Air Canada regional jet on a runway at New York's LaGuardia Airport on 22 March heard an air traffic controller shout "stop, stop, stop" but did not initially realise the warning was directed at his vehicle, federal investigators revealed on Thursday. The collision killed both pilots of the aircraft and sent around 40 people to hospital, making it the deadliest crash at LaGuardia in 34 years.
The National Transportation Safety Board (NTSB), which released a preliminary report into the incident, said the sequence of events unfolded over just seconds. Air Canada Express Flight 8646, a CRJ900 regional jet operating from Montreal with more than 70 people on board, had been cleared to land on Runway 4 at 11:35 p.m. About two minutes later — and only 25 seconds before impact — the fire truck's crew asked permission to cross the same runway. A controller granted clearance just 12 seconds before the plane touched down. Nine seconds before the crash, the same controller frantically radioed: "Stop, stop, stop, stop. Truck 1. Stop, stop, stop, stop." By the time the turret operator aboard the truck understood the warning was for him — after hearing his vehicle specifically named — the truck was already on the runway. A second after the warning, the plane's landing gear made contact with the ground, and the aircraft slammed into the fire truck. Pilots Antoine Forest, 24, and Mackenzie Gunther, 30, were killed. A flight attendant, still strapped into her seat, survived after being thrown onto the tarmac.
The NTSB identified a chain of compounding system failures. A crash-prevention technology called ASDE-X, installed at LaGuardia and 34 other major US airports to track all aircraft and vehicles on the ground and alert controllers to dangerous runway incursions, failed to generate any audio or visual alarm. Investigators said this was partly because the fire truck lacked a transponder, and partly because the proximity of the six-vehicle convoy — which included four fire trucks, a stair truck and a police vehicle — prevented the system from distinguishing individual units. Runway entrance lights, which function as stop signals for vehicles crossing active runways, remained illuminated until roughly three seconds before the collision, offering little practical warning time.
The broader operational context added to the pressure on air traffic controllers that night. Flight delays had pushed arrivals and departures after 10 p.m. to more than double the scheduled number, according to data from aviation analytics firm Cirium. A dozen flights arrived in the roughly 40 minutes before the crash, with planes landing every few minutes. Simultaneously, controllers were coordinating the emergency response to a strong odour reported in the cabin of an outbound United Airlines jet — the incident the fire convoy was responding to when it attempted to cross the runway.
The preliminary report stops short of assigning blame, as is standard at this early stage of an NTSB investigation. Nevertheless, it points to an alignment of failures — technical, procedural, and situational — that together overwhelmed the safety systems designed to prevent exactly this kind of accident. Investigators are expected to continue their examination of air traffic control procedures, emergency vehicle protocols, and the adequacy of runway safety technology at busy urban airports.