As lower Manhattan descended into a nightmare of ash and rubble on Tuesday, Brooklyn - the raffish, tumbledown City Across the River - suddenly became a safe haven.

Throngs of Manhattanites, unable to leave by car or subway, crossed the East River bridges on foot, anxious to escape the billowing cloud of smoke emanating from the World Trade Center and the threat of further attacks. Hundreds of them, reaching the bottom of the Williamsburg Bridge and heading southward, found themselves in the uncharted territory of Williamsburg, home of the Satmar chasidim.

Struggling with maps, vainly trying to use their cell phones, nervously scanning the sky every time a plane passed over, New Yorkers from all walks of life turned for guidance to groups of bearded men in black cloaks, women with scarves over their shaved heads pushing baby carriages and earlocked children with yarmulkes.

At the corner of Roebling and Lee streets in the heart of chasidic Williamsburg, a group of men set up an improvised refreshment stand, stocked with drinks and pastries. Among those inviting people to stop and take some refreshment was Abe Cohen, who said he had decided the evening before not to go to his business uptown.

"This is just terrible, we feel so helpless," he said. "All we can do is give people some food and drinks, show them the way. Everybody shows unity in such a situation."

When asked about possible attacks in the neighborhood, he pointed to the hundreds of people walking quietly in the streets. "There is no more fear in this neighborhood than in any other place in America. What should we do, hide? Hopefully, it is over."

One woman, who identified herself only as Mrs. Lieberman, was walking her baby around the neighborhood. She said her other children were in school, and there were no plans to bring them home early. "Everybody is nervous, but the children were already in school when it happened," she said. "And we have to go on."

At the Viener Yeshiva on Bedford Avenue, children were noisily playing in front of the entrance and pointing at the cloud of smoke hovering over lower Manhattan, across the river. Heskel Friedman, a school official, said that many parents had called, but that only "a few" had come to take their children home.

"The school principals in the neighborhood decided not to send the kids home so as not to increase the panic," he said.

In the yeshiva, which hosts some 1,000 children, and in several other schools, there was no visible police security on hand. Many chasidim said that the police personnel normally guarding the area had all been called to Manhattan. Today a stranger could enter the building with a backpack unimpeded. "We don't feel in danger at all," said Mr. Friedman. Most of the men and women along the streets said the same thing.

"Anyway, we know everything is in G-d's hands, so why worry?" said one young man who declined to give his name.

Chaim Pollack, who works in a neighborhood medical facility, said he was "deeply concerned, like every American is concerned. This is just like a movie. Planes crashing into the Twin Towers!"

Mrs. Lieberman agreed. "I thought America was very protected so I'm very surprised this happened. They'd better get those people who did it."

Although most of the people interviewed said they had never expected such an attack to take place, Simon, a worker for Hatzoloh, the city's Orthodox Jewish volunteer ambulance service, explained that "this was something waiting to happen because of the overly lax attitude of the U.S. authorities."

"Some people took advantage of the good nature of the American people," he added, while monitoring on his walkie-talkie the movements of the ambulances going in and out of Manhattan. "And I am sure that after the emotions come down, some people will blame it on the Jews. CNN will do its usual spinning."

A man standing nearby said someone riding a bike had yelled at him that it was "because of you Jews."

Mr. Cohen and others, however, insisted that this was essentially an attack against America and not against Jews.

"This is just a terrible day for America," he concluded, while inviting an African-American with a rasta haircut to stop for a minute and have a drink.