Officials say a 23-year-old customer got stuck inside the building at 580 Fifth Avenue around 7 p.m. and was finally freed around 6 a.m. Wednesday.
It's believed the customer was inside a DGA security vault to access his safety deposit box when he got trapped.
Authorities say employees inside the building closed the vault not knowing the customer was still inside and once the vault door is closed, it operates with a time clock -- which means the door can't be opened until it reaches a certain time.
"There was a customer inside the vault at the time that it closes. Once it's closed, it's on a timing mechanism. That vault does not reopen until a certain amount of time passes," FDNY Chief John Sarrocco said.
Customer freed from jewelry vault in Midtown
The building has a number of jewelry businesses inside. Officials believe the secured room with a timed lock mechanism is one of the many safety precautions inside the building.
Employees have no way to override the system.
Rescue crews spent more than 9 hours trying to breach 30 inches of concrete and metal plating. Authorities say they ultimately decided to stop that process for the safety of the customer inside the vault.
Officials say the man trapped inside the room was physically fine and there were no safety or oxygen concerns. Rescuers were able to monitor his condition with video and also communicate using a phone system.
Firefighters ran a hose to the basement of the building to keep the dust down and cool the tools.
Once he was freed, he was checked out by EMS and sent home.
DGA Security provides secure storage options for business in the Diamond District.
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