I’d just sat down to dinner with my wife Saturday evening, in the big white-tiled back room of a restaurant on the Upper West Side, when the lights went out—not all at once but one fixture failing softly after the other, like a deck of cards being slowly shuffled. We diners glanced around in acknowledgement of the change, but mostly just kept talking to our tablemates. Probably just a blown fuse after too much A.C. We asked the waiters what they knew, as if inquiring after an extra napkin. Nothing yet. Soon, though, as the air grew swampy and the room began to feel like the outdoors, a previously invisible back door was popped open, and the entire kitchen staff started filing out of the restaurant and into its shallow back yard. That kind of exodus makes me nervous; my mind ran quietly through the short list—terror, fire—of things that could be catastrophically wrong. It was just dark and hot in the kitchen, somebody said, meaning to be soothing. Nothing would be getting cooked for a while. Somebody else said that all the lights were off on the block. I tried to check Twitter, but my browser wouldn’t work. Waiters started telling patrons that they could leave, that their dinners were now on the house.

These, of course, were the first moments of a blackout that darkened not only Sixty-third Street and Broadway, where we were eating, but a long swath of Manhattan’s West Side, affecting more than seventy thousand Con Ed customers. (Somewhat uncannily, Saturday, July 13th, was the forty-second anniversary of the 1977 blackout that left the city without power for twenty-five hours. The first person to alert me to this odd anniversary was my mother, whose apartment, on West 104th Street, was mercifully spared, and whom, despite my phone trouble, I was able to reach via text message.) But we didn’t know that yet. Just a neighborhood disturbance, we still hoped. We were supposed to be seeing a play at Lincoln Center, so we walked there, a couple of blocks up, betting that the show would go on. No luck there. A harried-looking Lincoln Center employee, wearing a headset and a sweaty shirt, told us that, sorry, the play was cancelled. We overheard a pair of older women who’d had their screening of “Toni Morrison: The Pieces I Am” cut short. “I wanted to see every second of every minute of that thing,” one of them wailed.

By now even the street lights were dead, and the people and cars on the road moved slightly gingerly, except for the buses, which just kept swooping up Amsterdam and Broadway, making their stops and zooming through intersections. Outside the theatre, we fell into a conversation with a man and a woman who had walked down seventy flights of stairs from his rooftop, at Hudson Yards, then walked a mile and a half north—all just to see the show. Now they were sorry to have left at all. “This would have been a good sunset from up there,” he said, sort of happily softening, as New Yorkers often do, at the prospect of a few hours without power. We reminisced about the blackout of 2003—a big one, but with little of the looting of 1977. My wife, Renée, and I had both been out of town. That night, the man with the apartment at the Yards had been sitting in on a rehearsal of the Martha Graham Dance Company. The light had twinkled away as the dancers floated through their motions. “That was a fun day,” he said. We said goodbye and wished one another a nice blackout.

After a while, inevitably, we began to walk. No need, we figured, to risk going underground and getting stuck in a tunnel. At Columbus Circle, the mall was closed. A reporter named Neil Vigdor, a nice guy in shirtsleeves and khakis, his Times badge hanging from his neck, stopped Renée on the corner of Sixtieth and Broadway to ask her a few questions. “We’re just going to walk for a little bit and see what happens,” she said, when he asked how we’d be getting back to Brooklyn. Another lady, seeing Vigdor’s badge, muttered, “Oh, from the newspaper,” and hung around, maybe hoping to get asked something. We headed down Eighth, which by now was thick with walkers. The bars along the avenue had stayed open; people were drinking in the dark. Some regular people had jumped into the intersections, acting as a volunteer corps of crossing guards. When that many people are walking in the same direction—the whole west side of the street, it seemed, had turned into a southbound shuttle—they tend, unconsciously, to gather in clumps, like marathoners grouped according to pace. Before long, we’d drifted into a slipstream with a woman named Olivia, maybe our age or a few years younger, who wore an orange shirt and a scarf wrapped around her forehead. She, too, was trying to get back to Brooklyn. “Brooklyn” was by far the word that I overheard most. Everybody was trying to get back there after an ill-fated jaunt into the city. “This is why I stay in Brooklyn,” Olivia said, and several people around us grunted in agreement. After a century and a quarter, Brooklyn’s still what it was before New York’s boroughs were consolidated, on New Year’s Day, 1898: a more or less autonomous suburb, the river’s distance more than enough for thousands of parochialisms to bloom. I grew up in Manhattan and have only lived in Brooklyn for four years—now, longing for Flatbush Avenue, I finally understood.

I wondered aloud what Bill de Blasio was doing. “Nothing,” Renée and Olivia said, almost perfectly in synch. As it turned out, “Hizzoner” was among the cornstalks and arbitrarily entitled voters of Iowa, dithering about whether he’d make it back to his suddenly dark city. Into that void stepped the speaker of the City Council, Corey Johnson, who turned his Twitter feed into a hub of information about the outage. Instantly there were jokes that, two years before our next municipal elections, Johnson had already become mayor. Whoever actually wins that title after de Blasio’s done having fun with it, they’ll need to say something serious about the creaking infrastructure of the city, ever more apparent these days. Now that our phones were working again, and we understood the magnitude of the outage, we thought of people hanging helplessly in elevator shafts—a shared horror for Renée and me—and of all the places in the city, especially hospitals, that must have backup generators. “Generator” is one of those words, along with “transformer” and “levee” and a few others, that comes up only on days like this. You surprise yourself with your vague awareness of them when the vocabulary becomes necessary. As we approached Times Square, and the sun began to set on so many unlit buildings, midtown, usually so impressive, looked a bit flimsy, like a model of itself ready to be mowed down by a movie monster. Retail workers lounged in front of their now closed stores—two guys in matching 7-Eleven shirts leaned against their storefront, greeting people as they passed. Lines at hot-dog carts and falafel trucks were crazily long. Two women outside a Chinese-food place, improvising, hawked bottles of water for a dollar. Lots of weed was being smoked. We almost got on the subway at Forty-second and Eighth, but we could see a crowd sitting on the stairs. At Thirty-fourth, Olivia decided to try it anyway. We said a weirdly warm goodbye—we were sort of friends by now.

We walked over to Seventh Avenue, where the trains seemed to be O.K. We got on one, and, just as we’d settled in, every light in the place went off, and the station became a nightmare. We hustled back above ground before the train doors could close. We walked back west, where we saw thousands of people walking down immobile escalators in Madison Square Garden. One of Renée’s co-workers had been at the Jennifer Lopez concert there, and now, a very disappointed-looking woman told us on the street, the concert was being evacuated. One minute, Lopez had been singing—the next, a crowd of thousands was sitting in the dark.

Down we walked, stopping briefly for water at an unfazed CVS. Just before we found an idling yellow cab on Seventeenth Street, after almost fifty blocks of walking, we saw two friends, guys in tank tops, leaving the store where they presumably worked and starting down the sidewalk. “Apparently there’s a blackout? In Manhattan?” one of them said into his phone. “The trains are fucked,” he said. “We have to figure out how to get back to Brooklyn.”