A history-making blackout was slowly being reversed in the eastern United States and Canada Friday, amid growing questions as to what caused the electrical distribution grid failure that cut off power to an estimated 50 million people.
In the northeast, parts of the midwest and north into Canada, lights and air conditioning started to come back on Friday, hours after a paralyzing blackout.
Parts of New York City had power restored early Friday, though city officials urged non-essential workers to stay home.
New York Mayor Michael Bloomberg said emergency officials were inundated with calls overnight, but that there was no increase in crime related to the blackout.
"They [emergency workers] responded to 80,000 911 [emergency] calls, more than double the average," he said. "Three thousand firefighters put out 60 serious fires, up from an average of 10 a night. But almost all of the 60 appear accidental, many of those we investigated seem to be from candles."
Mayor Bloomberg says there were 800 elevator rescues in the wake of the power outage. He said it would be some time before New Yorkers could count on using the city's vaunted subway system again.
Thousands of New Yorkers and visitors were stranded in the city, unable to get home, and looking for anywhere cool to camp for the night.
This man spent the night at Penn Station, a major rail station in the city.
"I was downstairs in Penn Station, and it was very hot, the smell of diesel was atrocious," he said. "They actually evacuated it twice, just to try and air out something, open up some doors on both sides, get some cross-ventilation, and then get some people back in. You do this at 10:00 p.m., and 2:00 a.m. It gets challenging to people."
The blackout extended eastward to Connecticut, and westward toward the upper midwest, including Michigan and Ohio, and north into Canada.
Power was coming back to some parts of the city of Cleveland, but the city's mayor, Jane Campbell, went on television to urge residents to take it easy.
"Particularly, if there is a way you can live without air conditioning, open the windows, take a walk, drink a glass of ice water, something other than using your air conditioning would be really helpful," she said.
Officials also said it may take a while for Cleveland's water supply to resume normal operation because of the power outage.
Power was also returning to the Canadian province of Ontario, Friday.
As yet, there is still no official explanation of the cause of the cascading blackout that began late Thursday.
President Bush was quick to assure the nation that the power grid failure was not related to terrorism.
"One thing I can say for certain is that this was not a terrorist act," said president Bush.
But a number of public officials are now demanding to know how the power failure could have affected so many people so quickly.
"This should not happen," said New York Governor George Pataki on NBC's Today program. "We are in 2003. We are the most sophisticated society in the world, and we have to have an energy system that is reliable, and where this type of systemic failure does not occur. And, we need to know those answers. And, I am sure the president shares our concern, and will work to get those answers."
Power officials say they hope electricity will be fully restored within the next day or two. In the meantime, they are urging residential users to cut back on power, as much as possible.
The 2003 blackout affected an estimated 50 million people, and easily surpassed the famous 1965 power outage in the northeast that cut power to about 25 million people for a day in New York and much of New England.