A man died after he breached Denver International Airport and collided with an airplane.

Airport employees did not notice the breach until it was too late, according to a statement from authorities on Tuesday, as the man hopped over an 8-foot fence and onto the tarmac, where he was struck by a plane carrying 231 passengers.

The death on the runway is the latest example of the ongoing challenge of preventing intruders from accessing major airports. Denver International Airport is spread out over 53 square miles of vast plains northeast of the city.

The 41-year-old trespasser triggered alarms late Friday night as he entered a remote area about 2 miles from the airport terminals. But security personnel mistook the alarms for a herd of deer in the vicinity.

Authorities said the man committed suicide. However, no note was found at the scene. Sterling McLaren, the chief medical examiner for the City and County of Denver, said the cause of death was determined based on scene investigation, record review and autopsy results.

A Frontier Airlines flight en route to Los Angeles had to evacuate its passengers via emergency slides after the incident caused a fire in its engine. 12 people sustained minor injuries and five were transported to the hospital. Phillip Washington, CEO of the airport, stated that four of those individuals have since been released.

Black and white footage released by the airport captures a person in the distance waving their arms and walking toward the runway. They enter the runway at a slight angle, and seconds later, a plane can be seen speeding past. The plane struck the person with its right engine, and the engine erupted in flames.

Minutes before the man scaled the fence, a ground radar system in the area activated, setting off an alert. Washington said that when an airport employee checked surveillance cameras, they saw a herd of deer in the same area but initially did not spot the intruder.

“The camera screen was alternating between wildlife and the man. There were some ditches around, so the man would disappear from view momentarily,” Washington said.

He said federal authorities had notified the airport about the trespasser. Washington explained that airport staff were unable to intervene because the location was remote and the time elapsed between the man climbing the fence and reaching the runway was very short.

The man was struck and killed by a Frontier Airlines flight that was taking off at 150 mph as he crossed about 650 feet from the fence to the runway.

McLaren, the coroner, said the plane’s engine was the cause of the man's death, characterizing it as a "deliberate act that resulted in foreseeable fatal consequences."

Trespassing at airport perimeters is a common problem, with dozens of incidents occurring nationwide each year, according to security expert Jeff Price, who served as Denver Airport’s deputy director of security in the 1990s. The airport is surrounded by approximately 36 miles of perimeter fencing, which airport officials stated they inspect on a continuous basis.

By Chief Reporter Sung Ku Hong, NNP / Special Dispatch NNP info@newsandpost.com