The crash occurred around 11:45 p.m. on Sunday when an Air Canada regional jet arriving from Montreal struck an airport fire truck traveling across the runway to respond to a separate incident aboard another plane.

According to air traffic control audio, the pilot of that other plane — United Flight 2384 — reported a “weird odor” was causing flight attendants to feel ill while the plane was waiting to take off. The pilot declared an emergency and requested to return to a gate and for firefighters to respond.

Audio recordings from the airport control tower indicate the truck was initially cleared to cross the runway before a controller tried to pull it back to avoid a collision. The unnamed controller repeatedly told the vehicle to stop and diverted incoming aircraft from landing. He said later in the recording: “I messed up.”

Photos and videos from the crash’s aftermath show the jet’s nose crushed and tilted upward, with debris hanging from the mangled cockpit. Stairways used to evacuate passengers were pushed up to the emergency exits and the damaged emergency vehicle lay on its side nearby.

Weather at the time of the crash included moderate winds of about 7 knots and visibility of around 4 miles (6.5 kilometers) with mist and fog conditions, according to Bryan Bedford, head of the Federal Aviation Administration.