The person killed had jumped a perimeter fence, airport officials said.
DENVER, Colorado — A Frontier Airlines plane struck and killed a pedestrian on a Denver International Airport runway late Friday, forcing pilots to abort takeoff and evacuate 231 people after smoke and an engine fire were reported, officials said.
Frontier Flight 4345 was departing Denver for Los Angeles when the collision happened about 11:19 p.m. on Runway 17L. Airport officials said the pedestrian had jumped a perimeter fence and was hit about two minutes later while crossing the runway. The person had not been publicly identified by Saturday and was not believed to be an airport employee. The National Transportation Safety Board was notified, and the runway remained closed while investigators worked at the scene.
The Airbus A321 was carrying 224 passengers and seven crew members, Frontier Airlines said. After the impact, smoke was reported in the cabin and pilots stopped the aircraft on the runway. A brief engine fire was extinguished by the Denver Fire Department, airport officials said. Passengers left the plane using emergency slides and were taken by bus back to the terminal. Airport officials said 12 people reported minor injuries and five were taken to hospitals. No deaths were reported among passengers or crew members.
Radio traffic captured the urgency of the response after the pilots told the tower they were stopping on the runway. The crew reported that the aircraft had hit someone and that there was an engine fire, according to air traffic control audio cited by several outlets. The evacuation followed soon after as emergency vehicles moved onto the airfield. Denver International Airport said emergency response and investigation work continued into Saturday morning. Frontier said it was gathering more information and working with the airport and safety authorities.
The airport said the pedestrian reached the runway after breaching the airport perimeter. Officials had not said by Saturday why the person entered the secured airfield, where the person came from or how the person avoided detection before reaching Runway 17L. Airport security personnel were inspecting the perimeter fence after the crash. The airport said the person was hit about two minutes after jumping the fence, a short timeline that left investigators focused on access, surveillance records and the sequence of alerts before the aircraft began its takeoff roll.
The incident disrupted operations on one runway at one of the country’s busiest airports, though airport officials said most passengers from the Frontier flight later departed Denver on another aircraft. The plane involved in the collision remained part of the investigation. The aircraft’s engine, runway surface and available video or sensor records were expected to be reviewed as investigators worked to determine exactly where the pedestrian entered the runway and when the flight crew first had a chance to see the person.
Frontier Airlines said passengers were safely evacuated as a precaution after the pilots aborted takeoff. The airline did not release the names of any crew members. Denver police, airport officials, fire crews and federal safety officials were involved in the response or investigation. Authorities had not announced whether the pedestrian carried identification, whether any vehicle was found nearby or whether the person had any known connection to the airport, the airline or passengers on the flight.
By Saturday, the pedestrian was dead, the passengers had been removed from the aircraft and Runway 17L remained closed for the investigation. Officials had not released a full investigative timeline or the pedestrian’s identity.
Author note: Last updated May 9, 2026.