People from New York City to Toronto will likely long remember what they were doing when the lights went out during Thursday's massive power outage.
Bewildered office workers got stuck in elevators or trekked down flight after flight of stairs; dazed crowds streamed into the streets; and stranded subway riders waited in hot, stalled cars until they were given the go-ahead to evacuate.
Some people panicked during the outage, which affected more than 15 cities and evoked memories of the Sept. 11 terrorist attacks, but many remained calm.
Al Viscuse of California, who was in a New York City subway near the Museum of Natural History, said no one panicked when the power failed.
"I was surprised there were no emergency lights in the subway," Viscuse said, adding that his 11-year-old nephew Alex Wander of Queens, N.Y., suggested that "everyone use their cell phone lights and get out.'" Some were stranded in New York City subways for more than two hours.
Big Apple tourist Cindy West from Molone, N.Y., said she was in her Times Square hotel when the massive power outage hit American and Canadian cities — including Detroit, Cleveland and Ottawa — at about 4 p.m. ET.
"The whole upstairs (of the hotel) went pitch black," said West, who was with her husband Dan on a 30th anniversary-gift trip from their children. "We were hoping to see (the Broadway musical) 'Mama Mia' tonight."
In Massachusetts, Kim Hicks of Baltic, Conn., was on the Cyclone roller coaster at a Six Flags amusement park in Agawam when the power stopped. "We sat there about 20 minutes and they finally came to walk us off," she said. The park regained power a short time later.
In Toronto, streetcars preparing to transport workers around downtown for the evening rush hour ground to a halt, sending riders into the street to hail taxicabs.
Some people ended up directing traffic on their own.
Wearing a suit and tie, Peter Carayiannis waved vehicles through one busy intersection. "I've been doing this for about 45 minutes because nobody else is," he said. The situation was similar in Manhattan.
Elsewhere, the scene was more chaotic.
In Cleveland, Olga Kropko, a University Hospitals labor and delivery nurse, said the hospital was using its backup generators and had limited power. "Everyone is very hot because the air conditioning is off," she said. "Our laboring moms are suffering."
Nurse Mary Horan, who has an office in Grand Central Station, was stuck outside the closed terminal along with scores of other people, Reuters news service reported.
"Everybody just flipped out," said Horan, describing the scene at her workplace. "Suddenly you start thinking about 9/11."
The streets around Grand Central were packed, but the vibe was eerie and few people spoke. One nook of the station was open and a food vendor was selling water to parched New Yorkers. It was stifling hot and pitch black. The sound of an alarm could be heard ringing from down in the subway.
Steve Kravec of Connecticut was one of the many outside Grand Central. He said his fiancée was waiting for him.
"I'm just sitting against a tire. You just have to roll with it," he said. "I thought, damn, I'm short on cash. Hopefully I'll just squeak by." Kravec figured he could stay with a friend who lived nearby.
An American Red Cross disaster service van parked in front of the Grand Hyatt near the station gave water out to lines of thirsty New Yorkers.
Jessica Nottes was on top of the Empire State Building when power failed, according to Reuters news service.
"We had to walk down 86 flights of stairs," she told Reuters. "I kept thinking about the Twin Towers and how I would get down. But everybody was calm."
Subway workers had to lead hordes of passengers out of the dark tunnels and underground platforms to the street level.
Andre Bruce of Queens, N.Y., said he was working at his desk in Long Island, where his JP Morgan Chase office is located, when the place went dark and the building was evacuated. People were stuck in the elevators, he said, and those who could leave were told to go home.
"I have no food in the refrigerator, and most of that is spoiled already," Bruce said. "I don't have a flashlight, so I can't even go into my building and take the stairs."
Lines for pay phones were up to 10 deep in Manhattan, and crowds were overwhelming the few delis and food shops that remained open. One deli worker was only letting people in one at a time.
Some people seemed to be making the most of the blackout. One man sat on the street selling beer out of a cooler for $3 apiece. It is illegal to drink alcohol on the streets; many passersby were staring at him.
“The cops got better things to do,” he said, by way of explanation.
Another group had popped champagne and were toasting each other in front of their apartment building.
Doug Edwards of West Chester, N.Y., was trying to reach his wife at home but not having much luck getting through on his cell phone. He said he planned to head to Bryant Park to relax.
"I have no idea how I'll get home," said Edwards, who works at an ad agency in Midtown Manhattan. "I'm just going to pull up a chair and sit under the trees."
Fox News' Marla Lehner, Garett Nadrich and The Associated Press contributed to this report.