A video posted on Facebook late Sunday evening shows a passenger on a United Airlines flight from Chicago to Louisville being forcibly removed from the plane before takeoff at O’Hare International Airport.

The video, posted by Audra D. Bridges at 7:30 p.m. Sunday, is taken from an aisle seat on a commercial airplane that appears to be preparing to take flight. The 31-second clip shows three men wearing radio equipment and security jackets speaking with a man seated on the plane. After a few seconds, one of the men grabs the passenger, who screams, and drags him by his arms toward the front of the plane. The video ends before anything else is shown.

A United spokesperson confirmed in an email Sunday night that a passenger had been taken off a flight in Chicago.

"Flight 3411 from Chicago to Louisville was overbooked," the spokesperson said. "After our team looked for volunteers, one customer refused to leave the aircraft voluntarily and law enforcement was asked to come to the gate.

"We apologize for the overbook situation. Further details on the removed customer should be directed to authorities."

Bridges, a Louisville resident, gave her account of the flight Sunday night.

Passengers were told at the gate that the flight was overbooked and United, offering $400 and a hotel stay, was looking for one volunteer to take another flight to Louisville at 3 p.m. Monday. Passengers were allowed to board the flight, Bridges said, and once the flight was filled those on the plane were told that four people needed to give up their seats to stand-by United employees that needed to be in Louisville on Monday for a flight. Passengers were told that the flight would not take off until the United crew had seats, Bridges said, and the offer was increased to $800, but no one volunteered.

Then, she said, a manager came aboard the plane and said a computer would select four people to be taken off the flight. One couple was selected first and left the airplane, she said, before the man in the video was confronted.

On Monday, United released a statement from CEO Oscar Munoz: "This is an upsetting event to all of us here at United. I apologize for having to re-accommodate these customers. Our team is moving with a sense of urgency to work with the authorities and conduct our own detailed review of what happened. We are also reaching out to this passenger to talk directly to him and further address and resolve this situation."

They bought their tickets. They knew what they were getting into.

United Airlines says a man wouldn’t give up his spot on an overbooked flight Sunday.

So, according to witnesses and videos of the incident, he was pulled screaming from his seat by security, knocked against an arm rest and dragged down the aisle and back to the terminal at Chicago’s O’Hare International Airport.

United refused to answer questions about the incident, which horrified other passengers on the Louisville-bound flight. An airline spokesman only apologized for the overbooked flight, and said police were called after a passenger “refused to leave the aircraft voluntarily.”

What happened was captured on cellphone video by at least two passengers.

Tyler Bridges recalled trouble starting almost as soon as he and his wife boarded.

An airline supervisor walked onto the plane and brusquely announced: “We have United employees that need to fly to Louisville tonight. … This flight’s not leaving until four people get off.”

“That rubbed some people the wrong way,” Bridges said.

Passengers were offered vouchers to rebook, he said, but no one volunteered.

So the airline chose for them.

A young couple was told to leave first, Bridges recalled. “They begrudgingly got up and left,” he said.

Then an older man, who refused.

“He says, ‘Nope. I’m not getting off the flight. I’m a doctor and have to see patients tomorrow morning,’” Bridges said.

The man became angry as the manager persisted, Bridges said, eventually yelling. “He said, more or less, ‘I’m being selected because I’m Chinese.’”

A police officer boarded. Then a second and a third.

Bridges then began recording, as did another passenger — as the officers leaned over the man, a lone holdout in his window seat.

“Can’t they rent a car for the pilots?” another passenger asks in the videos.

Then the man, out of frame, screams.

One of the officers quickly reaches across two empty seats, snatches the man and pulls him into the aisle.

“My God!” someone yells — not for the first time.

He goes limp after hitting the floor.

“It looked like it knocked him out,” Bridges said. “His nose was bloody.”

His glasses nearly knocked off his face, the man clutches his cellphone as one of the officers pulls him by both arms down the aisle and off the plane.

“This is horrible,” someone says.

“What are you doing? No! This is wrong.”

And with that, Bridges said, four United employees boarded and took the empty seats.

They were not popular among the passengers, he recalled.

“People were saying you should be ashamed to work for this company,” Bridges said.

And it wasn’t over.

In another video, the man runs back onto the plane, his clothes still mussed from his forcible ejection, frantically repeating: “I have to go home. I have to go home.”

“He was kind of dazed and confused,” Bridges said. He recalled a group of high school students leaving the plane in disgust at that point, their adult escort explaining to other passengers: “They don’t need to see this anymore.”

The airline eventually cleared everyone from the plane, Bridges said, and did not let them back on until the man was removed a second time — in a stretcher.

In the end, Bridges and his wife got to Louisville about three hours late.

“It was a pretty tense flight,” he said.

Airport officials haven’t returned calls about the incident — though United Chief Oscar Munoz tweeted that everyone at the airline was upset about it.