Story highlights Agent was taken to an area hospital as a precaution. He passed a drug test and was discharged, Alaska Airlines says

The cargo hold is pressurized and temperature controlled

(CNN) An Alaska Airlines flight was forced to make an emergency landing Monday after its pilot reported hearing unusual banging.

Flight 448, which had been bound for Los Angeles, returned to Seattle.

Upon landing, a ramp agent was discovered inside the front cargo hold, according to a statement from the airline. The agent, who is an employee of Alaska contractor Menzies Aviation, told authorities he had fallen asleep, the statement said.

He appeared to be in OK condition. The cargo hold is pressurized and temperature controlled. The plane was also only in the air for 14 minutes, Alaska Airlines said.

JUST WATCHED Report: Trapped employee fell asleep in plane's cargo bay Replay More Videos ... MUST WATCH Report: Trapped employee fell asleep in plane's cargo bay 01:25

CNN affiliate KOMO spoke to Marty Collins, a passenger on the plane.

Read More