A man was visiting his safety deposit box in Manhattan just before 9 p.m. on Tuesday when the vault containing the box was closed and locked with him still inside, authorities said. 

Fire officials said they had constant communication with the 23-year-old man while he was inside the vault at DGA Securities on Fifth Avenue at West 47th Street, which caters to the surrounding Diamond District.

Rescue units spent several hours working to breach the 20-by-40-foot vault, but determined the safest option was to wait until the lock reopened on its timer.

“Once it's closed, it's on the timing mechanism. That vault does not reopen until a certain amount of time passes,“ FDNY Deputy Assistant Chief John Sarrocco said at a news briefing. 

Firefighters watched video footage of the man inside to monitor his health and other conditions.
 
“The process was started to breach the wall, about 30 inches of concrete. We started doing that. We got to the point where we got to the metal plating,” Sarrocco said.

"We determined that after about 10 hours, we'd hold off and see if the doors opened automatically. The problem with the plating is we'd have to use torches, which would affect the environment," he added.
 
Fire officials said the torch used to get through the metal plating would have created dangerous smoke conditions inside the vault. Since the man was not in any danger, they waited for the lock to reopen.

It finally did around 6:15 a.m. on Wednesday.

“The vault opened on its own. It's on the timing mechanism," Sarrocco said. "And he just was released from the vault. He's fine."

Once the man who was stuck overnight left the building, he did not answer any questions from the press. NY1 has reached out to DGA Securities for a statement about the incident, but has not yet heard back.