The Lucas County jail lost electricity about 6:50 p.m. Tuesday, and inmates were restricted to their cells in response, Sheriff John Tharp said.
Debbie Paul of Toledo Edison said that crews working to fix an electrical problem at the Ohio Building downtown tripped another electrical feeder, causing the jail to go dark.
Ms. Paul said he expected power to be back on by 10 p.m., but as of 4 a.m., sheriff's deputies said the jail was still in the dark.
Sheriff's deputies, corrections staff, and Toledo police patrolled outside the jail.
A backup generator powered emergency lights inside.
"We have inmates locked down. We have plenty of perimeter security outside," Sheriff Tharp said. "The bottom line is we need to make sure the perimeter's secure and everybody's safe, which we are."
The cause of the outage was not immediately known. Crews were working to restore power.
"Honestly, this is just another reason we needed a new jail. I'm sick of it," Sheriff Tharp said. "I'm disgusted with the poor facility we have here. Our officers are doing the best they can do.''
Toledo police dispatchers told crews that new inmates were not being booked into the jail during the outage. Anyone taken into custody in Toledo was to be held temporarily in the Safety Building, police said.