Fourteen minutes after the flight departed at 3:15 p.m. PT, the pilot declared an emergency and landed at Seattle-Tacoma International Airport.
After landing, an employee of Menzies Aviation was found inside the cargo hold, which is pressurized and temperature controlled, according to a statement from Alaska Airlines.
"He told authorities he had fallen asleep," wrote the airline.
The employee was able to walk off the plane but was transported to hospital as a precaution.
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