Southwest Airlines said Flight 4236 arrived in Phoenix safely from Colorado Springs in a statement.
Southwest Airlines spokesman Dan Landson said: “Initial reports indicate that while the flight was charging taxes to the gate, a customer on board exited the plane through a rear galley door. “The captain of the flight stopped the aircraft and notified Air Traffic Control (ATC).”
It is not clear how the plane’s doors were opened.
The Phoenix 19 Fire Department captain, located at the airport, was notified of the incident around 8 a.m., Captain Todd Keller of the Phoenix Fire Department said in a statement.
The man landed on the runway and made his way to the fire station, entered the building and locked himself in his dorm room, Keller said.
The fire chief added: “After a few minutes, the firefighters were able to unlock the door for the adult male student.
Authorities responded to the incident, after which the flight “continued to the designated gate,” Southwest Airlines said.
A Phoenix Police spokesman told CNN they were “aware of this incident, and at this time the investigation is ongoing.”
It is unclear whether the man will face charges.