A dead woman was found entangled in machinery in a baggage-processing area at O’Hare international airport in Chicago on Thursday.

Larry Langford, a spokesperson for the Chicago fire department, said firefighters were called to the airport at about 7.45am for a report of a person pinned in machinery used to move baggage. He said they discovered the woman entangled in a conveyor belt system in a baggage room.

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

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

Firefighters turned the scene over to police investigators, and Langford had no more details. The Chicago police department’s communications office said in an email to the Associated Press that the woman was found unresponsive and pronounced dead on the scene. Detectives have opened an investigation, the office said.

The police communications office initially said the woman was discovered at 2.27am, creating confusion about why firefighters and paramedics did not arrive for more than five hours.

After checking with the police department about the timing, Langford said that he was told surveillance footage shows the woman walking in the baggage room at 2.27am. The communications office issued a second statement Thursday afternoon saying that surveillance video shows the woman entering the room at 2.27am. She was actually discovered at 7.30am, prompting a 911 call.

The footage only shows her walking and does not show what happened to her.

Nathaniel Blackman, a police spokesperson, clarified during a phone interview with the Associated Press that no one was watching the surveillance cameras in real time and investigators reviewed the footage after the woman’s body was discovered.