A 73-year-old diabetic woman spent six hours trapped in a bank after employees accidentally locked her into the building, authorities said Friday.

Marian Prescher of Laguna Woods went to her local Bank of America branch Wednesday to look over contents in her safe deposit box and was given use of a privacy room to examine the valuables, authorities said.

Employees left her in the room when they closed the bank at about 6 p.m.

"They forgot she was there," Orange County sheriff's spokesman Jim Amormino said.

Prescher told KCAL-TV that she had not taken her medication with her because she only expected to stay a few minutes. She apparently passed out, bruising her right cheek when she fell to the floor.

Her niece, Louise Bariny, was supposed to take her out to dinner and began looking for her around 6:30 p.m.

But she didn't think to look in the bank.

"This is ridiculous," Bariny said. "Who would ever think that they could get locked in a bank?"

Shortly after midnight, deputies received a call from a cleaning person who discovered the woman, Amormino said.

Prescher was unconscious and cold to the touch when authorities arrived. She was taken by ambulance to a hospital, where she was treated and released.

"She's doing fine," Amormino said, adding it was fortunate she was found hours before the bank was scheduled to reopen.

"She may have died," he said. "It just seems to be a terrible oversight."

Prescher said she knew nothing about what happened until hospital employees revived her.

"And I was just, 'You've got to be kidding me,"' she said. "I just couldn't believe it, that they would leave me in there."

Bank of America said in a statement it had "reached out to Ms. Prescher and her family and we hope for her full recovery."

"Obviously this is a terrible situation and we regret that this happened," Bank of America said, adding the incident was being investigated.