An American Airlines flight bound for Philadelphia from Los Angeles was diverted to Phoenix after a passenger made "alarming" statements referencing the September 11 terrorist attacks, police said.
The passenger was removed from American Airlines Flight 754 at Phoenix Sky Harbor International airport on Thursday and taken to a psychiatric facility for evaluation under an involuntary hold, Sergeant Vince Lewis, of Phoenix, said.
"We had a situation where right after takeoff a passenger stood and walked to the first class section, where he stood at attention there and refused to take his seat," Lewis said.
"He began making statements that, although they were alarming and threatening in nature, gave the flight crew the indication (of possible mental health issues)," he said.
Lewis said some of the passenger's comments referenced the 2001 attacks on New York and Washington and his beliefs about the government.
The flight, which departed Los Angeles International Airport at 8.38am (Pacific Time), carried 150 passengers, three infants and six crew members, and was refueled and allowed to continue on to Philadelphia, a spokesman for American Airlines said.
A spokeswoman for the Phoenix airport declined comment, referring calls to police.