Phones stopped ringing.
Air conditioners ground to a halt. Traffic lights went black, leaving startled motorists to fend for themselves. Computers snapped off.
For office workers, the day came to an abrupt early end. Even Mud Hens baseball was postponed.
Others, like electric utility workers, and police and fire crews, faced a long, grueling night ahead.
People had to be rescued from elevators, roller coasters, and traffic accidents.
The lights flickered off about 4:15 p.m. yesterday in Toledo and all over southern Michigan and northern Ohio, leaving the entire region awash in confusion.
People were left in the dark, in the heat, their information only coming from battery-powered radios on the few stations still operating. Even many cell phones wouldn't work.
To say people were frustrated was an understatement.
“The hottest day of the summer and this,” said Len Cohen, 34. “The house is going to be an oven. I hope we get power soon. I don't know if I have a flashlight. By the time I get to a store, there won't be anything left.”
For some, the outage lasted only minutes. For others, it could last days.
Millions were affected in Ohio and Michigan.
The blackout stemmed from an explosion at a Commonwealth Edison plant in Niagara Falls, said Matt Butler, spokesman for the Public Utilities Commission of Ohio. “As a fail-safe along the way, power plants began to shut down, including the nuclear power plants.”
That included the Fermi II nuclear plant near Monroe.
Utilities were scrambling to restore power last night, but said the effort could take days as they checked for damage that may have been caused by a shock to the system.
Most of downtown Toledo had power back around 9 p.m.
Detroit Edison said it likely would not restore power to most of its 2.1 million affected customers at least through the weekend.
Downtown Detroit will not have its electricity today, and all businesses will be shut down, said Tony Early, CEO of DTE Energy, Detroit Edison's parent company.
One-sixth of the widespread power outage was centered in the Detroit system.
So many people had air conditioners, fans, and other electric gadgets running that power companies feared it would drain the system again.
Power companies were urging their customers last night to cut down on the use of air conditioners and electric appliances.
“If everyone turns their A.C. on, we're going to be back to where we were at 4:15 p.m.,” said Chuck Krueger, a Toledo Edison spokesman.
Reaction ranged from humorous to fearful.
“The first thing that came to mind was, `I know I paid my electric bill,'” said Malcolm “X” Alexander, a resident of Riverside Apartments.
The first question many people asked each other when the power went out: Is this a terrorist attack?
“It was kind of scary at first, but nothing's blown up yet,” said Rod Miller, of Perrysburg.
James Johnson, 52, was in the worst possible place when the power went out - in an elevator at the four-story Vistula Heritage Apartments at Erie and Locust streets.
“I was going from the first floor to my apartment on the second floor. I had just checked the mail. The elevator just stopped,” he said. “I just sat on the floor. I yelled a few times.”
“The air was getting to me. I was hot. That's what was getting to me,” he said. After about 30 minutes, another resident decided to check the elevator and heard Mr. Johnson's yells. She got a maintenance man to pry open the doors.
The blackouts were so sporadic Toledo Edison couldn't say precisely what areas were without power, and what had been restored.
But the company said at one point or another, almost all of its 370,000 customers did not have electricity.
Detroit Edison reported 2.1 million customers without power, including Detroit and areas all the way over to the thumb of Michigan, and the company had not restored much of the power last night.
Consumers Energy, which provides service to Lenawee, Hillsdale, and Monroe counties in Michigan, said that as of 10 p.m. 50,000 of its 1.7 million customers were without power.
In some areas, the lights flickered but the power stayed on, or the electricity went out for as little as a minute.
The outage hit the northern part of Ohio first, then rolled quickly to the west, stopping in the Toledo area.
“It was a cascading effect when it got to Toledo and caused our systems to go down,” Mr. Krueger said.
Some sections of Sylvania and Perrysburg had electricity back in a matter of a half hour or so, but it wasn't fully restored until about 7 p.m. in those areas.
There were brief, scattered outages in Wood County, with downtown Bowling Green going without power for just 40 minutes. Except for a few traffic signal interruptions, Fulton County had no reports of power losses, sheriff's deputies said.
Mayor Jack Ford spent the evening touring the city, meeting with local emergency officials and telling citizens to stay at home.
“Clearly the simulations and all the planning that has occurred since 9/11 is paying off,” he said.
Detroit Edison's first priority was to restart its coal-fired coal plant in Monroe, the nation's sixth-largest coal plant.
In northwest Ohio, the first signs of the problem occurred in the Catawba Island area, where an outage was reported at 3:15 p.m. Parts of Findlay also lost power about the same time.
Within 30 minutes, electricity was restored to much of suburban Toledo and many parts of the city. But the return of power was spotty.
On Heatherdowns Boulevard, one side of the street had electricity while the other didn't.
In downtown Toledo, the outage struck when many government employees were leaving work.
Police reported about 90 percent of the city's traffic lights were down, causing chaos and numerous accidents at intersections.
Toledo police said portable stop signs were put up at intersections throughout the city.
Firefighters rescued a half dozen people from elevators.
While FirstEnergy and the other power companies struggled to get the system back up, businesses and schools were shutting down.
Power went out at 4:12 p.m. at the Farmer Jack on Cherry Street. The store stayed open, but the outage was already costing them yesterday afternoon.
An employee said the store had to throw out hundreds of dollars worth of deli products, including sandwich meats. As the outage continued, the store started talking about tossing frozen foods.
People were stuck at the top of roller coasters all over Cedar Point amusement park in Sandusky. There were 30,000 guests at the park. George Durant III, 16, of Haverhill, Mass., said everything went silent when the electricity went out.
“After a few minutes I noticed a few people were trembling,” Antoine Dell, was on top of the Gemini when the blackout hit.
“The park got extremely quiet. Everyone sat there. Everyone was nervous. From where I was you could look out across the park and see everyone else stuck, too,” he said.
Two state prisons and four youth detention centers in northern Ohio were still operating on generators last night, said Orest Holubec, press secretary for Ohio Gov. Bob Taft.
The governor was on vacation at a family summer home in Quebec. Lt. Gov. Jennette Bradley oversaw the state's assessment of the blackout.
At about 7:45 p.m., the state activated its emergency operations center and Ms. Bradley presided over the state's response to the massive power failure.
“The good news is we are hearing reports of power being returned to some areas,'' Mr. Holubec said.
Cleveland Mayor Jane Campbell expressed concern about Cleveland's water supply because of the power failure.
State emergency officials said the Ohio National Guard couldn't transport water to Cuyahoga County unless the governor declared an emergency in the Cleveland area, which he had not by 9 p.m. last night.
Dave Rinebolt, executive director of Ohio Partners for Affordable Energy in Findlay said he was not surprised that northern Ohio lost power especially since Davis Besse is not operating.
“The ability to transfer power into the FirstEnergy service territory is limited by design so they can continue to collect from ratepayers for those nuclear power plants,” he said.
Mr. Rinebolt said utilities such as American Electric Power have more interconnections with other utilities - and as a result didn't suffer power failures.
“It's under-investment in the transmission system,” he said.
Last night, millions in the region were without power, including some in Toledo.
As evening turned to night, parts of the city remained dark. Some north Toledo residents feared trouble.
“Anything is possible in this neighborhood. Without lights, people feel that they can get away with anything,” said Pat Thomas.
Staff writers George J. Tanber, Tom Henry, James Drew, Luke Shockman, Tom Troy, Jenni Laidman, Mitch Weiss, Michael D. Sallah, and Larry P. Vellequette, contributed to this report.