A Frontier Airlines flight bound for Los Angeles reportedly struck a person walking on the runway at Denver International Airport on Friday night, according to the airline.

The incident happened during takeoff at around 10:15 p.m.

In audio traffic control recordings, the pilot can be heard saying the engine caught fire and smoke was in the aircraft before telling ATC the plane had to be evacuated on the runway.

Out of precaution, the passengers used slides to evacuate, Frontier Airlines said in a statement.

“We are investigating this incident and gathering more information in coordination with the airport and other safety authorities,” the Frontier statement read, in part. “We are deeply saddened by this event.”

The Airbus A321 had 224 passengers and seven crew members on board, according to Frontier. It was scheduled to land at Los Angeles International Airport at 12:16 a.m., but it appears it had been rescheduled for Saturday morning.

This is a developing story that will be updated as more information arrives.