DENVER — The National Transportation Safety Board is collecting information about the emergency evacuation of a Frontier Airlines aircraft that struck and killed a person on a runway during departure from Denver International Airport late Friday. The flight, bound for Los Angeles International Airport, reported striking a pedestrian during takeoff at approximately 11:19 p.m.

"We are gathering information about the emergency evacuation to determine if it meets criteria for a safety investigation," NTSB spokesperson Sarah Taylor Sulick said. The Airbus A321 was carrying 224 passengers and seven crew members.

Passengers exited the aircraft using emergency slides and were transported back to the terminal by bus. Firefighters responded to the scene. An airport representative said 12 passengers sustained minor injuries and five were hospitalized.

Several passengers said they remained inside the aircraft for several minutes while smoke accumulated in the cabin and were later left outside on the tarmac in cold conditions. A video taken by a passenger and circulated on social media showed the moment the person was struck, capturing the sound of a loud crash and people screaming.

"The individual who died was a trespasser who had breached airport security and deliberately scaled a permit fence and ran out on to a runway," U.S. Transportation Secretary Sean Duffy said. "The trespasser on the runway was then struck by Frontier Airlines flight 4345 during takeoff at high speed," he said.

The individual who was struck has not been publicly identified. Local law enforcement will lead the investigation into the security breach with assistance from the Federal Aviation Administration and the Transportation Security Administration.

Frontier Airlines is investigating the incident and gathering more information in coordination with the airport and other safety authorities. The FAA and the TSA are also assisting with the inquiry.