An admittedly intoxicated American Airlines baggage handler fell asleep on the job and ended up flying from Kansas City to Chicago in the belly of a Boeing 737.

The employee, who works for American subsidiary Piedmont Airlines at Kansas City International Airport, was working on the ramp for American Flight 363 on Saturday Oct. 27, when he apparently took a nap inside the cargo hold before the flight.

No one noticed him missing, and the plane took off at 5:52 a.m. local time with the worker in the forward cargo hold, airline and law enforcement officials confirmed.

The baggage handler, who has not been identified, wasn't discovered until the plane landed at O'Hare International Airport and parked at the gate just before 7:30 a.m. local time.

The employeewas interviewed by the Chicago Police Department, FBI and U.S. Attorney's Office, standard policy in matters involving aviation security.

He told law enforcement officials he was intoxicated and fell asleep, according to Chicago Police Department spokesman Anthony Guglielmi.

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The baggage handler was not charged with a crime and flew back to Kansas City on another American flight, he said.

American spokesman Ross Feinstein said the airline is investigating the matter and that the employee has been suspended.

“The American team is very concerned about this serious situation, and we are reviewing what transpired with our Piedmont and Kansas City colleagues,'' he said in a statement.

Feinstein said the 23-year-old employee was unharmed and did not request any medical attention when the flight landed in Chicago. The cargo hold is pressurized and heated, he said.

"We are grateful that he did not sustain any injuries,'' Feinstein said.

This isn't the first time an airline employee has been stuck in the cargo hold during a flight. In January 2017, a baggage handler was trapped in cargo on a United Express flight from Charlotte, North Carolina, to Washington Dulles. He was unharmed.

The most high profile recent incident occurred in 2015, when an Alaska Airlines flight from Seattle to Los Angeles had to turn around after pilots and passengers heard banging from beneath the aircraft shortly after takeoff.

A baggage handler was stuck in the cargo hold. He called 911 and said he was trapped in the plane but the connection was lost.

The American baggage handler did not have a phone on the flight. Feinstein said cell phone use is prohibited on the airport ramp.

Bill Waldock, professor of safety science at Embry-Riddle Aeronautical University in Prescott, Arizona, said being trapped in a cargo hold is probably "pretty claustrophobic'' but overall not as risky as it sounds since the area is pressurized and temperature controlled. Besides bags and packages, many airlines carry animals in the cargo hold.

"Particularly if they have live animals traveling, they'll keep it on average between 60 and 70 (degrees),'' he said.

Waldock counts as many as a dozen publicized incidents of airline workers becoming trapped in the cargo hold over the years, usually because someone fell asleep.

He said baggage handling is tiring work, with long shifts and heavy lifting.

"Every now and then they try to take naps because they're so tired,'' he said.

Waldock said airlines generally have two or three baggage handlers per flight depending on the size of the plane, plus a baggage handling supervisor. The supervisor is charged with making sure employees are accounted for after bags and other cargo are loaded, he said.

"But sometimes they slip through the cracks,'' he said.

A person familiar with the American incident in Kansas City but unauthorized to speak publicly about it said the napping employee was overlooked because no bags were loaded into the forward cargo hold and the door was closed.