LAS VEGAS — As bullets began flying into a crowd of country music fans, a pack of 300-plus people ran about a mile to the Las Vegas airport, where they kicked down chain-link fences, hobbled over razor wire and were briefly mistaken by security officials for being attackers instead of shooting victims.

Once they pushed past the fence at McCarran International Airport, some of them ran onto the tarmac as helicopters beamed searchlights toward people they assumed were intruders.

Airport authorities found people who were shot, bloodied and hysterical. Officials immediately halted air traffic, diverted two dozen flights to Phoenix and other cities and shut off some runway lights.

“I’m thinking to myself, I don’t know if the airport police know what’s going on yet,” said Mark Gay, who was near the front of the crowd as it ran to the airport. “We were running, running out of the dark. If the cops were on that side, they don’t know who we are. So it was: ‘Put your arms out when you’re coming in.'”

The large-scale airport breach highlighted the chaos that ensued after gunman Stephen Paddock opened fire on Oct. 1 from the 32nd floor of the Mandalay Bay casino-hotel on a country music festival down below, killing 58 people and wounding hundreds. The breach also raised questions about the security of the McCarran International’s perimeter as people were able to barge their way through the fences of one of the nation’s busiest airports.

“I don’t know that we ran across any breach that was comparable to this,” said Jenny Grover of the Government Accountability Office, which audits the Transportation Security Administration and reviews the agency’s security data. “Because of the uniqueness of the situation, I’m not really sure when it changed from a breach to a relief effort.”

McCarran has had a large number of perimeter breaches in recent years. An Associated Press investigation found that McCarran had 30 known perimeter security breaches between 2004 and 2016, making it the second-most breached major airport in the country by AP’s count.

Unlike other cities where the airport is on the outskirts, McCarran is located in the heart of Las Vegas. It’s only a few hundred feet from Las Vegas Strip properties like the Mandalay Bay and Luxor.

In the chaos of the massacre, some panicked concert-goers headed to the airport in the belief that it provided the best opportunity for safety, even if they had to force their way through the perimeter. At the time of the shooting, rumors were flying around about active shooters and bomb threats at a number of Las Vegas casinos, so they chose to get to the airport.

“We were making the decision – we’re headed to the airport. The airport seems like the most secure, safe place,” said Fred Rowbotham, an off-duty police officer from the San Diego area who was in the crowd that went to McCarran.

As it became clear that the crowd on the McCarran tarmac was fleeing gunfire, the airport repositioned workers to help with the evacuation and shepherded hundreds of the victims into secure facilities. For hours, they tended to the wounded and offered food, water, blankets, phone chargers and reassurance. Airport shuttle buses later took them to a central evacuation center.