US officials on Tuesday played down speculation that distracted air traffic controllers might have contributed to a deadly collision between an Air Canada jet and a fire truck at New York's LaGuardia Airport.  

Two pilots were killed in the runway crash late Sunday, which crushed the cockpit of the Bombardier plane and heavily damaged the emergency vehicle.

Media reports said investigators were probing whether airport traffic controllers were distracted by a separate odor issue on a United Airlines flight -- the emergency to which the fire truck was responding. 

"I would caution pointing fingers at controllers and saying distraction was involved," Jennifer Homendy, chair of the National Transportation Safety Board, told reporters.

"We rarely, if ever, investigate a major accident where it was one failure," she said.

"Our aviation system is incredibly safe because there are multiple, multiple layers of defense built in to prevent an accident. So when something goes wrong, that means many, many things went wrong," she said. 

Two air traffic controllers were working in LaGuardia's tower at the time, Homendy said.

In addition to their core roles, the two were handling departure clearances and ground traffic control, though it was unclear how those duties were distributed. 

Homendy said the staffing level was "common practice across the national airspace" for a midnight shift, noting however that her agency had previously raised concerns about fatigue.

"We have no indication that was a factor here, but it is a shift that we have been focused on in past investigations," she said. 

- No alert -

Homendy added that the runway safety system ASDE-X, designed to track aircraft and ground vehicles, did not generate an alert before the crash because the fire truck was not equipped with a transponder. 

The NTSB's lead investigator Doug Brazy said the board was analyzing more than 25 hours of cockpit voice recordings and 80 hours of flight data.

He said the final three minutes captured in the cockpit included the co-pilot transferring control to the captain six seconds before the recording ended. The reason for this was unclear. 

The collision was LaGuardia's first fatal accident since 1992.  

Located in the borough of Queens, LaGuardia is the third-busiest airport serving New York, handling 33.5 million passengers in 2024, according to port authority figures.

Deadly air crashes in the United States in recent years include a collision between a passenger jet and an army helicopter near Washington in January 2025 that killed 67 people.