Practically everybody who was around Boston on Nov. 9, 1965, has a story about what they were doing when the lights went out.
Barbara Fagan of Roslindale was cooking a leg of lamb when the Great Northeast Blackout set in. Jim Kelley, another Roslindale resident, saw his television shut off in the middle of a show.
And across the river in Cambridge, Jordan Beckler — then a student at MIT — said he was, of course, studying.
"We looked out our window and we couldn't see the Prudential Center," Beckler said. "All the lights were out."
A half-century ago on Monday, more than 35 million people across 80,000 square miles were hit by an electricity outage that remains one of the largest in North American history.
But many in Greater Boston were at first focused on more immediate concerns — only later learning about the scale of the blackout and of the concerns it raised about the security of our electric grid.
The historic power failure, which began at 5:17 p.m., engulfed eight states, trapped thousands in transit, and sparked a 300-person riot at Walpole State Prison.
The power outage lasted 13 hours, and the region became increasingly worried as the moments stretched on.
"As the scope of the blackout became known, one ugly word leaped into the minds of millions: Sabotage," read a front page story in The Boston Globe on Nov. 10, 1965. "And there was fear. Was this war? An enemy from outer space?"
In reality, the power outage was caused by human error. Utility maintenance workers in Ontario, Canada, accidentally reversed the current in a key circuit, launching a domino effect that eventually overloaded power grids in New York and New England.
According to Globe reports at the time, the estimated cost of the power failure was $100 million.
President Lyndon B. Johnson said the blackout, which occurred against the backdrop of an escalating Cold War, was "a reminder of the importance of the uninterrupted flow of power to the health, safety, and well-being of our citizens and to the defense of this country."
Kelley, now 65, said he wasn't worried about national security. He merely stayed awake waiting for the power to return. When that did not happen, he went to sleep and woke up for school the next day, like any other day.
The blackout was the main conversation topic of his classmates, Kelley said, but they did not yet know how big it was.
"We talked about people being stuck in elevators and wondered about what caused it," Kelley said. "But we didn't know it was the whole Eastern grid until much later."
Fagan, now 72, said she was shocked to learn that a power failure in Canada could affect Roslindale. In the days before social media and smartphones, fewer people understood the vast technological infrastructure that shaped their lives, she said.
"That was what made an impression," Fagan said. "You assumed it was your house or your neighborhood, and to know it extended further, it was mind-boggling."
Equally mind-boggling: Fagan still remembers eating the leg of lamb for dinner that night.
Paul Fagan, her husband, said he picked up his mother-in-law from a blacked-out building downtown and brought her to dinner.
"I remember I was able to get to work the next day. That was the important part," Fagan said.
Beckler, the former MIT student who is now 68 years old, said sometimes he forgets the blackout even happened.
"Nowadays it would have been a much bigger thing," he said Sunday, while taking a stroll at the Arnold Arboretum of Harvard University.
A similar incident occurred in 2003, when a power grid collapse affected 45 million people in the United States. That event prompted an address by President George W. Bush, which aired during prime time on most news stations.
As in 1965, there were fears that the outage was the result of the country's international enemies, but a federal task force found the cause to be malfunctioning software.
Laurie Noble, a 75-year-old real estate adviser who lives in Back Bay, said the more recent blackout seemed to be a much larger concern at the time that it happened. Even smaller outages have had a bigger effect on her life.
But she still remembers where she was in 1965.
Noble said her daughter Kim was a newborn at the time, and her family was living in River Vale, N.J.
The blackout presented several maternal challenges. Feeding and cleaning Kim was hard during the 13-hour darkness, as was changing her diaper, Noble said.
What did Noble do to pass time in the darkness? Read Russian novels by candlelight.
Specifically, the 864-page novel, "Anna Karenina."
"You end up having more resilience than you think," Noble said. "People have done without electricity for a long time."
Astead W. Herndon can be reached at email@example.com. Follow him on Twitter @AsteadWH.