After almost 29 hours in the dark, the lights were back on in all of New York City late Friday, ending a massive blackout that crippled the nation's largest mass transit system and left thousands of people scrambling to get home.

"We are 100 percent back," Consolidated Edison (search) spokeswoman D. Joy Faber said.

Power was fully restored to all 3.1 million Con Ed customers at 9:03 p.m. Still, the city was not completely recovered from the outage, which affected about 50 million people in eight states and Ontario.

Subway service was still down. But there was a "firm belief" that subway trains, halted where they were when power blacked out Thursday afternoon, would be operating fully sometime Saturday, New York City Transit (search) spokesman Paul Fleuranges said.

Transit officials had said it could take eight hours after power was restored to resume service for the system, which moves about 5 million riders daily.

But the Long Island Rail Road (search) and Metro North commuter rails said they would be running on regular weekend schedules on Saturday.

The blackout occurred at 4:11 p.m. Thursday; on Friday, thousands of people were still trying to get home, businesses were closed and workers were taking an enforced three-day weekend.

Con Ed spokesman Chris Olert said the utility was confident that power would remained fully restored; on Friday, parts of Staten Island experienced rolling blackouts, but Olert said he reduced demand over the weekend would help prevent further problems.

Hundreds of flights at the region's three major airports were delayed or canceled because of the blackout, but full electrical power was restored by Friday evening to LaGuardia Airport (search) and Newark Liberty International Airport and to all passenger terminals at John F. Kennedy International Airport.

The City Council finance office estimated the blackout cost the city up to $750 million in lost revenue, up to $40 million in lost tax revenue and up to $10 million in overtime pay for the first 24 hours after electricity went out.

Metro-North commuter trains were still crippled Friday, with only six diesel trains running from Grand Central Terminal, where crews barked updates through bullhorns.

Rumpled and unshaven commuters stranded in Manhattan overnight streamed on foot toward Grand Central Terminal and Pennsylvania Station.

"There were people sleeping in their chairs at the trading desks, others on sofas in the conference rooms," said Ted Sullivan, as he headed down Madison Avenue, hoping to catch a train home to Princeton Junction, N.J.

Workers who did make it home Thursday night were left at morning rush hour to squeeze onto buses, hail the rare cab, sweat it out on foot or take the day off.

"I think most people stayed home," Bloomberg said on his weekly radio show Friday morning. "You walk around the city and traffic is flowing."

But electricity wasn't, at least in some places.

Retiree Decia Medina had to trudge up and down 20 flights to her West Side apartment, which was still without power Friday afternoon. She was tired, needed to wash up and was living on junk food.

"I'm too tired — I've been up all day and all night," she said.

Sanitation Commissioner John Doherty said crews would work overtime through the weekend, collecting trash — much of it piled up on steamy sidewalks as New Yorkers cleaned spoiled food from warm refrigerators.

Officials opened several cooling centers for people perspiring in the sticky heat, and the parks department hooked up 600 sprinklers in parks throughout the city.

Thursday's dark night saw about 60 serious fires, the majority of which were sparked by lighted candles, Bloomberg said. One person died of a heart attack, a firefighter was injured and a police officer became ill.

The city received 80,000 calls to its 911 line — more than double the usual — and emergency medical personnel responded to 5,000 calls. Hundreds were rescued from elevators after the city lost power.

Public pools in many areas were open on Friday, but officials closed city beaches because of the health threat posed by sewage leaked into waters during the power crunch.

Sightseers were left to enjoy the parks or roam the streets as many tourist attractions were closed on Friday, including the Empire State Building (search), Statue of Liberty and Metropolitan Museum of Art, which usually draws 50,000 visitors on a weekend.

Some exasperated tourists simply made plans to bolt.

The airports were open, but travelers endured long lines — not just at ticket counters, but at pay phones and everything else. Many faced travel delays of several hours.

Across town at the Port Authority bus terminal, would-be passengers stranded for nearly 24 hours begged to board buses that idled outside. Some buses were operating, but the building and its ticket windows were closed, leaving drivers to sort out the chaos.

Dominik Scales, an Australian on his way to Arizona, was not impressed with his first trip to Manhattan.

"Everyone's walking around with these 'I Love New York' T-shirts," he grumbled. "I hate New York. I just want to get out of here."