DENVER — A Frontier Airlines flight bound for Los Angeles struck and killed a trespasser on a Denver International Airport runway late Friday night, prompting an aborted takeoff, an engine fire, and an emergency evacuation, according to airport officials and federal authorities.
Frontier Flight 4345, an Airbus A321neo carrying 224 passengers and seven crew members, was accelerating down Runway 17L at approximately 11:19 p.m. MDT on May 8, 2026, when the aircraft hit a pedestrian who had breached airport security minutes earlier. Airport officials said the individual scaled a perimeter fence and reached the active runway shortly before the collision.
The impact caused a brief engine fire and smoke inside the cabin, according to air traffic control recordings and statements from Frontier Airlines. The pilot immediately rejected the takeoff, radioing that the aircraft had struck someone and had an engine fire. Emergency slides were deployed, and all 231 people on board evacuated onto the runway before being transported by bus back to the terminal. Twelve passengers suffered minor injuries during the evacuation, and five were taken to local hospitals, officials said.
The pedestrian, who has not been identified, died at the scene. Authorities said the person is not believed to have been an airport employee.
U.S. Transportation Secretary Sean Duffy said the individual “breached airport security, deliberately scaled a perimeter fence and ran onto the runway” before being struck by the aircraft.
Local law enforcement, the FAA, and the TSA are investigating. The National Transportation Safety Board has been notified. Denver International Airport said an inspection found the fenceline intact, and investigators are working to determine how the individual accessed the airfield. Runway 17L was closed for several hours and later reopened after the scene was cleared.
Frontier Airlines said it is “deeply saddened” by the incident and is cooperating with authorities. Most passengers were rebooked on another Frontier flight Saturday morning.