His city is under water. There's no electricity, no water to drink. Broken gas lines cause flames to erupt from filthy floodwaters. Mobs loot stores and exchange shots with police. Hungry people fight over food. Dead bodies float through the streets while the living huddle on rooftops, awaiting rescue.

New Orleans Mayor Ray Nagin stares at the apocalyptic wreckage of his city from a window in his makeshift command post in the Hyatt hotel, which sits across a flooded street from City Hall. His wife and three children have been evacuated. He has sent most of his staff to higher ground in Baton Rouge. But he remains behind, like a captain determined to stay with his sinking ship.

"He's gonna be there until this thing turns around," says Don Hutchinson, the mayor's director of economic development, speaking on a cell phone from Baton Rouge. "He's showing the leadership a mayor should show."

He's not a politician, not really. Nagin, 49, was a cable TV executive at Cox Communications, a man with no previous political experience, when he beat out 14 candidates to win election as mayor in 2002. Back then, he was a fresh face in New Orleans politics, a young guy with a shaved head who promised to clean up a corrupt city.

"Ninety-five percent of the time, it's the greatest job in the world," he told New Orleans magazine in 2004, "and 5 percent, it's the highest pain you could ever imagine."

Back then, he could not possibly have imagined the pain he is witnessing in the aftermath of Hurricane Katrina, one of the worst natural disasters in U.S. history.

"My heart is heavy tonight," he said Monday, sitting in the studio of WWL-TV in New Orleans. Dressed in a white T-shirt topped with what looked like an unbuttoned police or firefighter's shirt, he ticked off a list of problems in his slow Nawlins drawl -- "80 percent of the city is under water . . . we have an oil tanker that has run aground that is leaking oil . . . you see flames sparking up from the water . . . we have buildings that look like a bazooka was shot through them."

With the TV lights gleaming off his head, he summed up the scene: "It's really kind of a surreal situation, like a nightmare that I hope we'll wake up from."

That was Monday night. Since then, things have only gotten worse. Yesterday at the New Orleans Convention Center, where more than 15,000 people have taken refuge, corpses lay out in the open and mobs angered by a lack of food and water battled with police.

"This is a desperate SOS," Nagin said in a statement released to the media. "Currently, the Convention Center is unsanitary and unsafe and we are running out of supplies for 15,000 or 20,000 people."

In the halls of the Hyatt yesterday morning, the mayor was mobbed by citizens demanding to know when they could go home, when normal life would resume.

"You need to listen very carefully," Nagin told them, according to the Associated Press. "For the next two or three months, in this area, there will not be any commerce, at all. No electricity, no restaurants. This is the real deal. It's not living conditions."

Somehow, as his city collapses around him, he remains calm.

"The mayor is a very confident, very levelheaded person," says Hutchinson. "He's not one to react on a personal level. He's not panicky."

"He stays very calm under fire, and he stays very focused," City Council member Jackie Clarkson, mother of actress Patricia Clarkson, told the AP. "Through all the demands coming at him from different directions, he's stayed very focused on human life."

Nagin was born in 1956 in New Orleans's Charity Hospital, one of the hospitals that have now run out of food and water and been besieged by looters. His mother worked at a lunch counter in a Kmart. His father worked two jobs -- a fabric cutter in a clothing factory by day, a custodian at City Hall at night.

A hotshot pitcher in high school, Nagin went to Tuskegee University on a scholarship, graduating in 1978 with an accounting degree. He worked for General Motors in Detroit, then for financial services companies in Los Angeles and Dallas. In 1982 he married a childhood friend, Seletha Smith. Three years later, Nagin was hired by Cox and he and Seletha returned to New Orleans, where they raised two sons, Jeremy and Jarin, and a daughter, Tianna. He was making about $400,000 a year when he was elected mayor, a job that paid $110,000.

"I'm going to need your help," he told his supporters the night he won the election. "I don't have a Superman undershirt on underneath this coat."

He promised to take on the city's entrenched culture of corruption and kick-start the economy. Flood prevention was not a major issue in the election, although it must have been on the new mayor's mind: In 2004, he told New Orleans magazine that his favorite book about the city was John Barry's "Rising Tide: The Great Mississippi Flood of 1927 and How It Changed America."

Yesterday, Nagin had more important things to do than talk about his personal reactions to the destruction of his home town. But Pat Owens, a 64-year-old woman living in Ocala, Fla., thought she knew what was going through Nagin's mind. Owens was the mayor of Grand Forks, N.D., in 1997, when the city of 50,000 was wiped out by the flooding of the Red River.

"It's like a nightmare," she says. "You're torn in so many different directions. You have to make decisions and you can't wait. You have to act immediately. . . . It's hard. You really feel like you're all alone."

She dealt with looting, angry citizens and an evacuation that was, she says, the biggest in U.S. history since the Civil War.

"I worked on adrenaline for months," she says, "because I didn't sleep. My staff and I worked 20 hours a day for weeks."

Dealing with the floodwater was tough enough, she says, but dealing with citizens was tougher.

"They were very testy because they couldn't go back to their homes," she says. "They blame the city officials for the flood. You are blamed for water coming in."

And then, when federal money finally arrives, she says, "people get so angry because somebody got more dollars than them."

Three years after her flood, Owens ran for reelection. She lost by about 300 votes.

"They just looked upon me as the flood mayor," she says, "and they think that if you're gone, the flood will be gone, too. I was very, very hurt."

Yesterday, she had a bit of hard-earned advice for Mayor Nagin: "You just have to do what you think is right, because you're not going to please everybody."

Adam Nossiter of the Associated Press contributed to this report.

New Orleans Mayor Ray Nagin and Louisiana Gov. Kathleen Blanco are briefed about the rising floodwater.

Former Grand Forks mayor Pat Owens empathizes with Nagin: "You really feel like you're all alone."