Investigation into what led to the deadly LaGuardia collision between plane, firetruck

The National Transportation Safety Board is sending a team to investigate the deadly collision at New York's LaGuardia Airport between an Air Canada plane and firetruck on a runway. According to ATC audio, an air traffic controller had given clearance for the vehicle to respond to another emergency involving an odor on a United flight, but moments later the controller realized his mistake and tried to stop the vehicle.