In less than three minutes, an intruder exploited a gap at Denver International Airport and stepped into the path of an accelerating Frontier Airlines jet with 224 passengers and seven crew aboard. The 41-year-old man, whose death the Denver medical examiner later ruled a suicide, slipped past motion detectors in a remote area of the airfield, scaled an 8-foot perimeter fence topped with barbed wire, and walked onto the runway late Friday night, airport officials said. The jet, traveling at roughly 150 miles per hour, struck the man, and an engine burst into flames, prompting the pilot to abort the takeoff and evacuate the aircraft. Twelve people sustained minor injuries.
The breach has ignited debate among aviation and security experts over the adequacy of perimeter defenses at the sprawling airport, which covers an area twice the size of Manhattan and is ringed by about 36 miles of fencing. Denver International Airport CEO Phillip Washington told reporters Tuesday that the facility had received “perfect scores” on federal airfield safety and perimeter integrity inspections, but he acknowledged that a ground detection alarm, triggered shortly before the man entered the airspace, was dismissed by a security worker who attributed it to a herd of deer.
“An individual who was working the cameras had mistaken it for a herd of deer, so there was a miss,” Washington said, adding that the perimeter fence is patrolled and continuously inspected. He maintained that making the fence taller or adding razor wire would not necessarily have prevented the intrusion because a motivated person could still find a way in.
Eric Chaffee, a law professor at Case Western Reserve University and an expert on risk, said the incident represents a clear security failure and called for new countermeasures. “People ought to be concerned. This was really an unprecedented risk. But now there is precedent,” Chaffee said. “There ought to be new measures put into place to prevent this type of tragedy.”
Other experts pushed back, arguing that the rarity of such dangerous events does not justify the enormous cost of blanket surveillance or impregnable defenses. Steven Wallace, former director of accident investigations at the Federal Aviation Administration, described the fatality as a “one-off event.” He noted that perimeter fences are primarily designed to keep out wildlife, not determined humans, and that there are no uniform standards for their construction. “I just don’t see how you’re going to think of and deal with every possible way a human could get into an airport,” Wallace said.
Former National Transportation Safety Board Chairman Jim Hall said the Denver case has likely raised the risk of copycat attempts. He urged the airport to invest in more personnel and improved camera monitoring. “With the amount of cameras and technology that is available, they need to address the problem,” Hall said. “They’ve had a failure, and they don’t need to have another one.”
Security consultant Jeff Price, who managed security at the airport in the 1990s, said perimeter breaches are a regular occurrence nationally — possibly dozens each year — but he added that the vast majority of trespassers do not pose a real threat. In 2020, a man died at Austin’s airport after being struck by a Southwest Airlines jet on a runway; police later determined it was a suicide.
On Tuesday, two law firms notified Denver officials that they are preparing lawsuits on behalf of Frontier Airlines passengers, alleging multiple security failures and seeking more than $10 million in damages. The firms did not provide specifics beyond claiming their eight clients suffered mental and physical injuries.
Airport officials said they are reviewing their protocols. The Transportation Security Administration, which oversees airport perimeter security, did not immediately respond to a request for comment.