The man hopped the airport perimeter fence, an airport spokesperson confirmed.

A man was struck and killed by a Southwest Airlines plane as it was landing on the runway of Austin-Bergstrom International Airport late Thursday, according to airport officials.

The man who died was not an employee at the airport and hopped the perimeter fence to gain access to the runway, Austin airport spokesperson Bryce Dubee confirmed to ABC News.

“We are treating it as a security breach,” Dubee said. “This is the first time we’ve had a runway incursion like this. We have had the occasional security breach, but no one has ever gotten onto an active runway at the airport.”

The Transportation Security Administration said in a statement on Friday that it “is conducting a check of the perimeter of the airport property with the airport’s security team.”

The pilot of the Southwest flight from Dallas to Austin reported the man on the runway to air traffic control after it was cleared to land.

“Where exactly do you see the man?” the controller asked.

“They are behind us now,” the pilot said.

Southwest Airlines said in a statement to ABC News that the aircraft “maneuvered to avoid an individual who became visible” shortly after the the Boeing 737 touched down.

Austin Police Department’s airport unit later discovered “an obviously deceased adult male” on the runway, a spokesperson for the police department said.

The scene was cleared overnight, according to an airport official, and the runway reopened early Friday morning.

Southwest said none of the 59 people on board the flight were injured in the incident and that it is fully cooperating with local law enforcement and the Federal Aviation Administration.

FAA investigators deployed to the scene last night. The agency has not confirmed whether or not the aircraft struck the victim.

A spokesperson from the National Transportation Safety Board said it is still gathering information and has not launched an official investigation at this time.