Anxious and frightened, the citizens had the mayor of New Orleans (search) surrounded. They wanted reassurance, answers, a firm date when normal lives could be resumed after Hurricane Katrina (search).

Ray Nagin (search) wouldn't give it to them. He listened calmly, not trying to escape the hotel corridor. But there was no sugarcoating.

"You need to listen very carefully," Nagin told them. "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."

Outside, it is sweltering chaos. A once-functioning American city is suddenly in a state of nature. But Nagin is calm, at least outwardly.

Facing the greatest challenge any mayor could face, he is, say those who know him, tackling the catastrophe methodically. He says everyone should leave — an unprecedented conclusion, but one he says is the only possible one in a city that has become uninhabitable.

As the overwhelming problems come up, one by one — whole neighborhoods destroyed, thousands needing rescue, thousands more who must be evacuated, no services and looting in the streets — Nagin focuses in, advisers say. Moving between city hall and a command post set up at the Hyatt across the street — both surrounded by water — the mayor searches for the quickest way out.

It will be weeks before this ex-businessman's stewardship of the crisis can be realistically assessed. For now, though, he is keeping the cool that has become his trademark in New Orleans.

One of the few moments of visible agitation was before the storm hit, when Nagin was trying to hustle as many residents as possible out of town. His warnings were dire and apocalyptic and, observers say, effective: 80 percent of the city evacuated.

"He's really calm. He's taking it very analytically. He's working his way down the problems," said Greg Meffert, the city's technology chief, and one of Nagin's principal advisers.

"A lot of people are wigging out," said Meffert. Not Nagin. While other top local officials sat in despair, Nagin refused to give in to it.

"Everyone said, 'Oh my God,' or whatever. He was very, very logical," Meffert said. "What he's been doing is funnel all the information, prioritize the tasks."

He's well-known for his laid-back style, his casual use of argot, and an untraditional discourse that includes few of the cliches of his political brethren. Now, that unflappable style is being put to its ultimate test.

"He stays very calm under fire, and he stays very focused," said Jackie Clarkson, a city councilwoman who has remained in the beleaguered city, unlike most of her colleagues. "Through all the demands coming at him from different directions, he's stayed very focused on human life," Clarkson said.

Nagin isn't a politician. He's a 49-year-old former executive with Cox Cable who entered politics for the first time in 2002, when he won an upset victory, coming out of nowhere to surprise the sophisticated political class in his native city.

A Democrat, he had engineered a first in local politics — a black man who nonetheless got decisive support from whites, particularly the business elite.

He immediately signaled a break with past practices at City Hall, zeroing in on corruption as a top problem. Analysts criticized the blunt approach. But Nagin's focus reassured the businessmen excluded from municipal contracts, who had become deeply wary of local government. Blacks have criticized Nagin in the past for being too accommodating to business demands. But the Poydras Street Corridor — where the city's office towers are located — remains enamored of him.

The business manager's style is in evidence now, as Nagin, at public appearances, establishes a chain of priorities, one by one: rescue those who haven't succumbed to the floodwaters yet, get the sick out, evacuate the Superdome, ship off those who remain.

He applauds the arrival of a U.S. Army general who is "kicking some butt," and offers a tough but analytical assessment of the looting: It began with desperate searches for food in a city where thousands are without resources, but quickly "escalated to this mass chaos."

The language is not sensational, but it is unsparing. His city has become a flooded hellhole, and Nagin makes no effort to disguise it.