One person was struck and killed by a Frontier Airlines plane two minutes after jumping a perimeter fence and crossing a runway at Denver International Airport late Friday, the airport said.

The pedestrian, who has not been identified, is not believed to be an airport employee, the airport said in a statement.

Flight 4345, an Airbus A321, was departing from Denver en route to Los Angeles and carried 224 passengers and seven crew members, Frontier Airlines said in the statement.

There are about 36 miles of perimeter fence surrounding the airport. An inspection after the incident found the fence was intact, but the airport said it will perform an “incident analysis” in the coming days and review its perimeter security program.

The airport said it uses video surveillance and a “combination of technology” to monitor the area and performs “continuous perimeter fence inspections.”

The runway has reopened and passengers evacuated from the plane were placed on other flights, according to the airport.

“The aircraft reportedly struck a pedestrian on the runway during takeoff,” the airline said. The incident happened at 11:19 p.m. local time, according to the airport. The flight had been scheduled to depart at 10:39 p.m.

“Smoke was reported in the cabin and the pilots aborted takeoff. Passengers were then safely evacuated via slides as a matter of precaution,” the statement said.

A brief engine fire was quickly extinguished by the Denver Fire Department, the airport said in a statement early Saturday.

Emergency crews responded to the scene and passengers were taken to the terminal. Twelve people reported minor injuries and five were transported to local hospitals, according to the airport.

Passenger Jose Cervantes said he had just started feeling the plane tilt up when he heard a thud.

“I looked to my right, and I just see the right wing just on fire and like, it’s exploding,” Cervantes told CNN affiliate KCNC. “The aircraft lands back down, and they kind of like swivel side to side, and then they stop, shut it off right away, and then the cabin starts to fill up with smoke.”

“I thought I was going to burn to death. You know, when I just saw the fire and the smoke, I just thought I was going to burn,” Cervantes said.

Cervantes’ mother was one of the passengers injured, he told KCNC. “My mom actually ended up going straight down the slide and like locking her knee when she hit the floor,” Cervantes said. “She doesn’t have any fractures, but we still gotta take her to the ER.”

Shaken by the incident, John Anthens, 56, and his 30-year-old son chose to skip their flight home to Nebraska and rent a car for the eight-hour drive.

Anthens said the incident was too traumatic. “I saw a little spark, and then I saw and heard a big explosion, like a bomb going off,” he told CNN, as he described seeing the engine burst.

CNN has reached out to the Denver Fire Department and Frontier for more information.

The National Transportation Safety Board is coordinating with the FAA, Denver International Airport operations and local law enforcement to gather informatino about the incident. The FAA confirmed to CNN it is investigating.

The NTSB told CNN it will only review the evacuation of the plane to determine if it meets the criteria for a safety investigation. It will not investigate the security breach or the trespasser.

Air traffic control audio, shared by the ATC.com app, captured the moment a pilot from the Frontier flight told controllers the plane “hit somebody.” Seconds later, a controller said emergency vehicles were being dispatched. “There was an individual walking across the runway,” the pilot can be heard saying.

The pilot told controllers there were 231 people and more than 21,000 pounds of fuel on board, according to the audio clip.

Data from flight tracking website Flightradar24 showed the plane was accelerating at about 146 mph at roughly 11:15 p.m. local time, before it aborted takeoff.

“The pilot stopped takeoff procedures immediately,” Transportation Secretary Sean Duffy said. The person, Duffy noted, had “deliberately” scaled the perimeter fence and run out onto a runway. “No one should EVER trespass on an airport,” he added.

“We are deeply saddened by this event,” Frontier said.

This story has been updated with additional information.

CNN’s Kareem El Damanhoury, David Williams, Yan Kaner and Sneha Dhandapani contributed to this report.

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