Emergency crews met a United Airlines flight from Charlotte immediately after it landed at D.C.’s Dulles International Airport over the weekend when it was discovered that a baggage handler had become locked inside the cargo hold.

The Charlotte Observer reports that United Airlines is investigating how a baggage handler from the Charlotte-Douglas International Airport became locked in a plane’s cargo hold for a 90-minute flight.

The man was not injured during the Mesa Airlines-operated flight, in which the plane reached an altitude of 27,000 and temperature inside the compartment reportedly dropped to as low as 30 degrees.

Authorities, including the Federal Aviation Administration, were notified shortly after the plane took off that it was possible a fellow baggage handler was locked in the compartment.

“It’s going to be an apparent baggage handler that got locked in the baggage compartment,” the dispatch call stated, as reported by NBC Washington. “It’s going to be in the rear cargo area. Should have been pressurized. Unknown injuries at this time.”

Upon landing, emergency crews opened the cargo area and found the man, who refused medical treatment.

For a short time, the incident was being investigated as a security concern, as the man was clad in his baggage handler uniform, but did not have is ID on him.

WBTV in Charlotte reports that authorities finally deemed the incident a “public accident,” however, it remains unclear how the man became locked in the cargo area.

This isn’t the first time a baggage handler has unexpectedly become a stowaway. In April 2015, an Alaska Airlines flight was forced to make an emergency landing after an employee fell asleep in the cargo hold.

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