A Frontier Airlines flight was forced to abort take-off after fatally striking a person who reportedly breached airport security and entered the runway at Denver International Airport late Friday night.

According to air traffic control audio, the pilot of Flight 4345 informed the control tower moments after the incident that the aircraft had hit someone while accelerating for departure. The pilot also reported an engine fire as the aircraft came to a stop on the runway.

Emergency crews responded quickly after smoke was seen inside the Airbus A321 cabin. Firefighters managed to extinguish the fire, while all passengers onboard were evacuated using inflatable emergency slides as a precautionary safety measure.

The flight, which was scheduled to depart for Los Angeles International Airport, was carrying more than 220 passengers along with crew members at the time of the incident. Airport authorities later confirmed that several passengers sustained minor injuries during the evacuation process, with some transported to nearby hospitals for medical evaluation.

Officials said the unidentified individual had allegedly climbed over a perimeter fence and entered the runway area just minutes before the aircraft began take-off procedures. Air traffic control had already cleared the plane for departure moments before the collision occurred.

Following a brief pause in communications, the pilot radioed the tower stating that the aircraft was stopping on the runway after striking a person who had been walking across the active runway area.

Transportation officials described the aircraft as moving at high speed during the incident. Commercial passenger jets typically reach take-off speeds between 150 and 180 miles per hour, making it nearly impossible for pilots to stop safely once acceleration is underway.

Authorities stated that the individual involved is not believed to have been an airport employee. Airport officials later inspected the perimeter fencing and reported no visible damage or security failures along the fence line.

Passengers onboard described a frightening scene as smoke entered the cabin shortly after impact. Some travelers reported hearing a loud thud before seeing flames near one of the aircraft’s wings. Videos and photographs shared online appeared to show smoke spreading through parts of the cabin as passengers prepared to evacuate.

After leaving the aircraft, passengers were transported back to the terminal while emergency responders secured the runway area. Most travelers were later rebooked onto another Frontier Airlines flight to continue their journey.

The affected runway remained closed as federal investigators began examining the incident. Aviation authorities and transportation safety officials are now investigating how the trespasser gained access to the restricted runway area and whether additional airport security measures may be required.

The incident has raised fresh concerns about airport perimeter security and runway safety at one of the busiest airports in the United States.