Chicago (CBS) — Six people, including a pregnant woman, became trapped on an elevator early Friday morning after dining at the Signature Room in the building formerly known as the John Hancock Center.

Chicago Fire Department Battalion Chief Patrick Maloney said firefighters got the call around 12:30 a.m. for a stuck elevator with passengers inside at 875 N. Michigan. When crews arrived on scene, they found that two of the elevator car’s cables had snapped.

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Otis Elevator spokeswoman Sarah Christy said the company sent a team to the building to help free the passengers.

“We understand how distressing this situation can be and are grateful that no injuries were reported this morning. There is nothing more important to Otis than safety,” Christy said in an email

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Rescue teams had to breach a brick wall in the building’s eleventh floor parking garage in order to safely reach the people inside. They had been in the elevator about two hours.

Maloney said the rescue effort was particularly difficult, because it was a blind-shaft type elevator, which means there are no openings between floors.

None of the six people rescued required medical attention. The cause of why the cables snapped is not known at this time.

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Otis Elevator crews were helping building management to repair the elevator.