Firefighters found a dead woman entangled in machinery Thursday in a non-public baggage-processing area at O’Hare International Airport in Chicago.

Larry Langford, a spokesperson for the Chicago Fire Department, said firefighters were called to the airport around 7:45 a.m. for a report of a person pinned in machinery used to move baggage. He said they discovered the woman entangled in a conveyer belt system in a baggage room.

Police said she was 57 years old but have not released her name.

The baggage room wasn’t publicly accessible, Langford said, and it’s not clear how she found her way into it. Scott Allen, a spokesperson for the U.S. Department of Labor, said an official with the Occupational Health and Safety Administration visited the scene and learned the woman was not an airport employee.