NEW YORK (AP) — The number of missing in America's worst terrorist attack soared Thursday to 6,333, with hundreds of foreigners added to the list of victims feared dead beneath the crumbled World Trade Center.

The number had been 5,422 for several days.

Mayor Rudolph Giuliani said the sudden jump reflected reports of foreigners buried after two hijacked jetliners brought down the twin towers Sept. 11.

The mayor has said there is little chance of finding anyone alive. The last survivor was found the day after the crashes.

The news was an unwelcome jolt on a day when the city had edged closer to normalcy, with the small steps of children walking back into schools and the return of traffic to the Brooklyn Bridge.

The exception was at ground zero, where rescue workers hunting for survivors toiled in vain for a ninth straight day. Forty U.S. senators toured the site for a firsthand look at the devastation.

Giuliani acknowledged that the 2,000-degree fire caused by the explosions of the two planes and the implosion of the 110-story towers make it likely that some victims will never be recovered.

"Even weeks ahead, while we're removing stuff, obviously we're going to be looking," Giuliani said. "Right now, the possibility still remains. They're slim, but they still remain."

According to the mayor, the British consulate said 250 British citizens were missing. He did not provide other numbers, but 63 countries in all are believed to have victims in the rubble.

The bodies of 241 people have been found so far. Of those, 170 have been identified by the coroner. There were funerals Thursday for eight of the more than 300 city firefighters lost in the attack.

Still, the curtain of sadness that has enveloped New York since the attacks parted a bit Thursday, as thousands of students who were driven from their classrooms near the Trade Center by the attack went back to school in classrooms away from the devastation.

It was a tight squeeze but not an unhappy one for many.

"I'm excited to be back," said kindergartner Jason Brilliant as he arrived at Public School 3 in Greenwich Village. "It was a long time because the World Trade Center went 'boom."'

Parents exchanged hugs and smiles outside the school's red doors.

"The kids were amazing," said teacher Julie Hiraga, who clutched the hands of two students as they ran for safety last week.

The Brooklyn Bridge — a pathway to safety for thousands as they fled the collapsing Trade Center — reopened two Manhattan-bound lanes to automobile traffic for the first time since the attack.

The delegation of senators, including Majority Leader Tom Daschle and Minority Leader Trent Lott, visited the Trade Center site for a look at the ruins.

"We're here because we recognize this loss must be shared not only by New Yorkers, but by all Americans," said Daschle, D-S.D.

The group pledged to help the city recover and rebuild. Last week, Congress approved a $40 billion package that includes help for New York, and the Bush administration has pledged to cover all cleanup costs.

"I've never seen anything comparable to what we've seen here today, the magnitude of it," said Lott, R-Miss. "It's so important that we come and see what we're dealing with."

Larry Silverstein, leader of a consortium that took over a 99-year, $3.2 billion lease on the complex in July, said he intends to rebuild — but not "a carbon copy of what was." Instead, he may construct four 50-story buildings.

The mayor said 6,291 people were injured in the attack and more than 80 area hospitals treated people afterward. At least 30 remained hospitalized at five Manhattan hospitals that saw the majority of patients following the attack.

Near the southern tip of Manhattan and not far from the Trade Center site, some residents were allowed into Battery Park City on Thursday for the first time since the attack. They were allowed just 15 minutes. Most emptied refrigerators of spoiled food and packed precious items into a suitcase or two.

When will they be allowed back to their homes?

"You can ask five different people, you get five different answers," said Jay Jaffe, 34, an equity trader who lugged some of his possessions through the rain.