A Frontier Airlines jet at Denver International Airport struck and killed a person who was running across the runway on Friday night after scaling a fence surrounding the airport.

According to a statement from the airport, Frontier Flight 4345 struck a pedestrian during takeoff at the airport around 11:19 pm on Friday. A brief engine fire occurred and was extinguished by the Denver Fire Department.

“Emergency crews responded to the scene and bussed passengers to the terminal. 231 souls were on board. Emergency response and investigation are ongoing. The NTSB has been notified. Runway 17L will remain closed while the investigation is conducted,” the statement added.

The airport confirmed the individual who was struck was killed in the incident and had been drawn into one of the engines.

On Saturday, Transportation Secretary Sean Duffy revealed that the person who was struck breached airport security, scaled the perimeter fence, and ran onto the runway.

“The trespasser on the runway was then struck by Frontier Airlines Flight 4345 during takeoff at high speed. The pilot stopped takeoff procedures immediately,” Duffy said in a post on X.

“The Frontier plane was then quickly evacuated while law enforcement and firefighters responded. Preliminary reports are 12 people were hurt, with 5 taken to the hospital. Local law enforcement handles airport security and is investigating with support from the FAA and TSA. No one should EVER trespass on an airport.”

Audio from air traffic control captured the pilot reporting the incident moments after impact. “We just hit somebody, we have an engine fire,” the pilot told air traffic control. “There was an individual walking across the runway.” Frontier Airlines said it is conducting an investigation into the incident.