Dietrick said that even through the headphones he was wearing, he could hear someone in the bathroom sounding "horrified out."
That's when the three marines gathered outside the toilet while an air hostess unlocked the door, according to the release. When it was open, the navy sport held the passenger with ribbons.
"I knew I had to step in when he became a danger to others and himself," Meinhardt said. "I didn't think twice about helping to restrain him throughout the rest of the flight."
After securing the passenger a seat, the Marines kept an eye on him for the remainder of the flight.
It is unclear why the passenger was appalled.
"At the moment, we cannot identify the airline or comment on the disposition of the passenger, as the incident is still under investigation," Marine spokeswoman 2nd SE Kayla Olsen told CNN.
The plane eventually arrived at Dallas Fort Worth International Airport after first being diverted to Los Angeles International Airport, so the passenger could be transported to a local hospital for a mental evaluation, the release states.
The U.S. Attorney's Office for the Central District of California and the FBI is continuing to investigate the incident, according to the release.