A Southwest Airlines flight from Los Angeles to Houston had to make an unscheduled landing in Corpus Christi, TX, after an unruly passenger tried to open the emergency exit door while the plane was in the air.

According to the Houston Chronicle, her fellow passengers said they could tell something was amiss: The woman had been shouting and walking backwards at Los Angeles International Airport before the flight took off on Sunday, and some wondered how she had been allowed on the plane.

One witness said that the woman spent the first few hours of the flight standing in the aisle yelling sporadically, until flight attendants attempted to get her to settle down. He says that’s when he heard a commotion and saw another passenger restraining the woman.

The woman who subdued the unruly passenger turned out to be an off-duty officer for the Cleveland Independent School District in Texas, according to the police chief.

“She had observed the irrational passenger attempting to open the exit door in mid-flight,” he told the Chronicle. “Fearing for her safety and the safety of everyone on the plane, she took action and was able to restrain the passenger.”

Her fellow flyers were grateful for her efforts.

“The rest of the passengers cheered when the off-duty officer came back on board, hailing her as a hero,” another passenger told the Chronicle. “If she hadn’t acted so quickly, things could have gone very differently.”

Southwest confirmed that the flight had been diverted after flight attendants informed the captain that there could be a “potential threat.”

“Following an uneventful landing, local authorities met the aircraft at a gate and removed the disruptive passenger,” the airline said.

The Federal Bureau of Investigation met the plane when it landed and took the passenger into custody. Due to the fact that the plane was in the air when the incident happened, they’ll be investigating the matter.

Passengers were delayed more than five hours in Corpus Christi — though they were allowed to leave the plane — eventually taking off at 5 p.m. and arriving an hour later at Hobby Airport.

She’s not the only unruly flyer to go for the exit door at the wrong time — on the way to Houston, no less: Last November, a United Airlines passenger opened the plane’s door and hopped out while the plane taxied. And in April 2016, a United Airlines flight attendant deployed a plane’s slide after it had landed at the same airport, rode it down, and walked away from her job.

This kind of behavior isn’t limited to Houston-bound flights, either: A Kentucky man was banned from flying on commercial airlines last year after he got into an altercation that ended with him trying to exit from an open door that wasn’t connected to the jet bridge.

Then there was the intoxicated British Airways passenger who tried to pry open the door mid-flight ; as well as the man who thought the airplane’s door was the bathroom and tried to open it at 30,000 feet; and the Virgin America passenger who reportedly masturbated in flight and then went for the exit door.

And it’s been awhile now, but you may recall another famous plane exit, that of JetBlue flight attendant Steven Slater. He became infamous in 2010 after he cursed out a passenger and then used the plane’s emergency slide to exit the plane and run away.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.