Frontier Airlines jet strikes, kills individual walking on runway at Denver International Airport

A Frontier Airlines flight taking off for Los Angeles from Denver International Airport on Friday night struck an individual walking on a runway, according to the airline and airport officials.

The incident occurred shortly after 11:00 p.m. local time on Runway 17L, the airline said in a statement early Saturday. There were 224 passengers and 7 crew members on board, Frontier said.

The person struck was at least partially consumed by one of the engines, an official confirmed to ABC News, causing a brief engine fire.

According to air traffic control audio obtained by ABC News, pilots reported an engine fire and smoke inside the aircraft following the incident.

Transportation Secretary Sean Duffy said Saturday the victim had breached airport security, deliberately scaled a perimeter fence and ran onto the runway.

The person was struck by the plane during takeoff at high speed, Duffy said.

Preliminary reports are that 12 were injured and five were taken the hospital, according to the secretary.

"Emergency response and investigation are ongoing," the Denver International Airport said earlier. "The NTSB has been notified. Runway 17L will remain closed while the investigation is conducted."

A source briefed on the incident told ABC News that airport security was inspecting the east perimeter fence on Saturday morning for gaps and the person struck did not appear to be connected to the work occurring on a parallel runway.

"We are investigating this incident and gathering more information in coordination with the airport and other safety authorities," Frontier Airlines said. "We are deeply saddened by this event."

Local law enforcement handles airport security and is investigating the incident with officials from the Federal Aviation Administration and Transportation Security Administration, Duffy said.

This is a developing story. Please check back for updates.