Southwest Airlines says a pressurization issue forced a flight from Phoenix to Atlanta to make an emergency landing in Texas.
The airline says its pilots and crew followed emergency procedures to divert and land at the nearest airport when the midflight malfunction occurred Saturday morning.
No one was hurt, though the plane's emergency oxygen masks were deployed.
Passengers on Southwest Flight No. 118 were delayed about seven hours.
The plane that landed in Amarillo has been taken out of service for inspection and repairs.