Josleen Wilson spent last Thursday night in her Manhattan apartment listening to Bush and Bloomberg and lesser-known cheerleaders describe the city as “festive” during the blackout. On Friday she watched her tropical fish swim to the top of the living-room aquarium, desperately seeking oxygen. At 2 PM she walked into the bedroom and shut the door.

At 6:05 PM on Friday, when the power came back on, she didn’t call her husband, who was in Boston. Or her mother, who was in California. Or me, her stepson in Chicago. She called Paul Hritz, the aquarium-service guy who lives across the street.

“She was my first phone call as soon as the electricity came on,” Hritz said that Sunday. The owner of Crystal Aquarium Service, he’s been making tank calls for over 20 years. He has more than 70 clients, most of them on the Upper East Side. Trained by his father, who owned the Crystal Aquarium Pet Store for more than 50 years and set up a tank for John Kennedy Jr. when he was still called John-John, Hritz has his own list of celebrity clients, including Harvey Weinstein and Kevin Kline and Phoebe Cates. Many of his current customers are the children of his father’s customers, and he has keys to town houses throughout the area.

“She called me, and I said, ‘I’ll be right over,'” Hritz said. “I had a feeling that it was going to be bad.”

Wilson’s three largest fish were floating in the water. “I said, ‘It looks like you lost two or three,’ and she said, ‘Oh, I’m not even gonna look,'” Hritz said. “She wouldn’t even look.”

The tank’s filtration system had gone off when the power stopped. More important, so had the air pump. Without filtration, aquarium water can sustain fish for as long as a couple of weeks. But without the little bubbles, and without air-conditioning, the water heats up and stagnates. “Cold water has more oxygen,” Hritz said. “Hot or warm water has less oxygen. So it’s all very conducive to death.”

If Wilson’s tank had been larger or her fish smaller, more might have survived. The final body count was nine.

It was the worst Hritz had seen since just after 9/11, when he’d gone to service the tank of a corporate customer whose offices were a block from the World Trade Center. The power had been off for more than a week, and the tank was foul. All six fish in it, including a small leopard shark, were stone dead. The cause of death was the same: lack of oxygen in the water.

Hritz did find some of Wilson’s fish alive. “I did a 50 percent water change, and then I filled the tank with cold water,” he said. “‘Cause cold water is– it’s almost like throwing cold water on your face.” He added some salt and Nova Aqua to remove the chlorine, and watched five fish start moving.

Afterward, Hritz took a cab to an apartment with two aquariums at 94th and Fifth. The owner was away in the Hamptons, and his tanks were fed by a system that might not have started back up automatically. “I was like, ‘I know if I go to sleep tonight I’m not going to be able to sleep, ’cause I know those fish are going to be dead.’ But they were OK.” All was well at his next stop too, a town house at 83rd and Lexington with three aquariums and a backyard pond. The koi in the pond, he said, “are surface breathers–not as subject to suffocation. No deaths there.”

One fish was belly-up at 86th and York, his final call that night. “The rest were all at the top, kind of gulping,” he said. “Like we’d do in smoke. Same thing with smoke and us–we’re gulping for air, they’re gulping for air.”

The customer told him that if he’d gotten there sooner he might have been able to save the dead one. “I explained that I had other customers,” Hritz said. “She understood.”

Two days later, on Sunday, he was worried about his other customers. No one had been to the midtown offices of his corporate clients since Thursday night. Many of his other clients had been in the Hamptons since then too. “This Monday is going to be the worst,” he said, “so I’m just trying to brace myself.”

During a brownout some years ago the power went out in Hritz’s father’s pet store, and he rented a gas-powered generator to run the air pumps for approximately 500 tanks. Hritz didn’t think that was an option for many of his customers, but, he said, “they make an electric battery-powered air pump.” New World Aquarium, at 38th and Third, sold 20 of them on Friday.

Wilson never thought she’d need one. “The instructions recommended them for people who live in places that experience power outages,” she said. “I thought, ‘Well, I live in New York. We don’t have power outages.'”

Hritz had wanted to tell her to get one but couldn’t. “There was no phone at all,” he said regretfully. “What am I going to do, climb 11 stories up to her apartment?”

Wilson said she was angry at the government for the blackout, angry that the people of New York got hit again. Then she stopped herself. “I watched them die, and there was nothing I could do about it,” she said. “I really liked those little guys.”