An American Airlines flight was diverted Wednesday evening after a passenger reportedly assaulted a flight attendant.
Flight 976 had departed New York’s John F. Kennedy International Airport and was headed to John Wayne Airport in Orange County, California, but was diverted to Denver because of the incident, the airline said.
Law enforcement apprehended the passenger at the gate, according to American Airlines.
The airline did not provide additional details or the flight attendant's condition.
“Acts of violence against our team members will not be tolerated by American Airlines," it said in a written statement. "The individual involved in this incident will never be allowed to travel with American Airlines in the future, but we will not be satisfied until he has been prosecuted to the full extent of the law. This behavior must stop, and aggressive enforcement and prosecution of the law is the best deterrent."
In a video statement, American Airlines CEO Doug Parker said a "very disturbing downside" to post-pandemic increased air travel are displays of "unruly behavior" that happen "far too often."
"This should not be part of their job," Parker said of American Airlines' flight attendants and crew.
"As to this individual, I can guarantee you he will never be allowed to fly American Airlines again," Parker said, calling "aggressive criminal prosecution" the best deterrent.
The case was investigated by the FBI and the Justice Department on Monday identified the suspect as Brian Hsu, 20, of Irvine, California. He was charged with interference with a flight crew and assault within the special aircraft jurisdiction of the United States, the Justice Department said in a statement.
A source close to the investigation told NBC News that the dispute was not over mask use. The passenger was allegedly bumped by the flight attendant during beverage service. Shortly after, he allegedly stood up, walked to the back of the plane, punched the flight attendant twice in the face, and then returned to his seat.
Mackenzie Rose, who was on American Airlines Flight 976, said she saw the flight attendant with blood on her face mask during the incident, which occurred while they were flying over Ohio, and photographed the suspect after their emergency landing in Denver.
Rose claimed on Twitter that the attack was over improper mask use.
"The reason for the assault, he didn’t want to wear a mask," Rose wrote on Twitter.
Denver Airport Police confirmed the flight was diverted into Denver around 6 p.m. and said the FBI is investigating.
The flight left Denver for Orange County about 9:30 p.m., according to American Airlines.
Reports of unruly behavior on planes, including violence against crew members, have increased since the start of the pandemic.
Data provided by the Federal Aviation Administration show 923 investigations have been initiated this year into violations of specific regulations or federal laws.
The number is up from 183 last year and 146 in 2019. Prior to 2021, the most investigations initiated in the 26-year period dating back to 1995 was 310 in 2004.
In May, a Southwest Airlines flight attendant lost two teeth after a passenger punched her in the face and pulled her hair, according to court documents. The attendant had asked the passenger to fasten her seatbelt, stow her tray table and properly wear her mask during the final descent.
The passenger told law enforcement that she was acting in self-defense, according to court documents.
She was charged in federal court with assault and interference with flight crew members and attendants and has pleaded not guilty, according to court records.
As of Tuesday, the Federal Aviation Administration has received 4,941 reports of unruly behavior by passengers this year, including 3,580 reports of mask-related incidents.
The rate of these incidents has dropped about 50 percent since record highs earlier this year, but FAA Administrator Steve Dickson said in September that progress needs to continue.
“This remains a serious safety threat, and one incident is one too many,” Dickson said in a written statement.
The FAA has no authority to prosecute criminal cases but can levy fines and implemented a zero-tolerance campaign in January that permitted it to issue fines without warning letters.
This year, the agency has brought more than $1 million in fines against passengers for the allegations of unruly behavior.