The National Transportation Safety Board (NTSB) has stated that the fire truck involved in the fatal LaGuardia plane crash was not equipped with a transponder. The board's chairwoman, Jennifer Homendy, stated that runway warning system failed to sound an alarm moments before the collision. Two Air Canada pilots were reportedly killed and several others were injured when the jet carrying 72 passengers and four crew collided with the fire vehicle. The control tower issued frantic last-minute warnings to the truck, but it is unclear if they ever heard them. The NTSB determined that one of the two controllers on duty cleared the truck to cross the runway 20 seconds before the fatal crash.