CHICAGO (CBS) — There have been many questions surrounding a woman who was found dead at O’Hare International Airport on Thursday morning after becoming trapped in a plane.

The woman was found trapped in a conveyor belt in Terminal 5 – the international terminal – and died at the scene, according to the Chicago Fire Department.

According to sources, the 57-year-old woman was in an area of ​​Terminal 5 that is off-limits to the public, but her presence there would not be considered a security breach as it did not occur in a high-security area.

She was found trapped in the conveyor belt of a baggage transport machine. How she got there was still unclear on Thursday afternoon.

Firefighters at O’Hare found the woman unconscious. They said they were called at 7:45 a.m.

According to sources reviewing airport video, the woman was seen walking around the area as early as 2:27 a.m. The exact time she entered the machinery was still unknown late Thursday.

The woman’s death was confirmed at the crime scene.

CBS News Chicago contacted the Occupational Safety and Health Administration (OSHA), which said it was not investigating the case because the woman was not an airport employee.

Her identity remains a mystery.

An autopsy will be performed Friday at the Cook County Coroner’s Office to determine the woman’s cause of death.