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.

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."

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.