A Frontier Airlines flight bound for Los Angeles struck and killed a pedestrian who had trespassed onto an active runway at Denver International Airport late Friday night, triggering an engine fire and the emergency evacuation of all 231 people on board.
The incident occurred around 11:19 p.m. MT on May 9, 2026, as Frontier Airlines Flight 4345, an Airbus A321, was accelerating for takeoff on Runway 17L. According to authorities, an unidentified individual deliberately jumped a perimeter fence and entered the runway shortly before the aircraft reached that section during its takeoff roll.
The pedestrian was fatally struck and partially ingested into one of the plane’s engines, causing damage and a brief fire that sent smoke into the cabin. The pilots promptly rejected the takeoff, declared an emergency, and the crew initiated a full evacuation using emergency slides.
“Tower, Frontier 4345, we’re stopping on the runway. Uh, we just hit somebody… we have an engine fire,” one of the pilots radioed air traffic control, according to public recordings of the transmission.
All 224 passengers and seven crew members evacuated safely. Twelve passengers sustained minor injuries, mostly from the evacuation slides, with five transported to local hospitals for treatment. No serious injuries were reported among passengers or crew. Denver Fire Department crews quickly extinguished the engine fire.
The aircraft was taken out of service due to the damage, and Runway 17L was temporarily closed.
In a statement, Frontier Airlines said it was “deeply saddened” by the tragic event and assisted passengers with rebooking on alternative flights to Los Angeles.
Authorities confirmed the deceased was a trespasser with no affiliation to the airport and not an employee. The perimeter fence was later found intact. The National Transportation Safety Board is leading the investigation, with assistance from the FAA, Denver Police Department, and airport officials.
U.S. Transportation Secretary Sean Duffy addressed the incident publicly, stating, “No one should EVER trespass on an airport,” while confirming the breach was deliberate.
Such events are exceptionally rare at major U.S. airports. While runway incursions involving authorized vehicles occasionally occur, a pedestrian successfully reaching an active runway at a facility as large and heavily secured as Denver International is highly unusual. Investigations continue into how the individual accessed the airfield and the full sequence of events.
As of early Sunday, officials had not yet released the identity of the deceased.
