Workers battled underground fires in the ruins of the World Trade Center on Friday, turning to more heavy equipment in an unofficial admission that hope of finding any of the 6,333 missing alive was all but lost. 
The teams working for a 10th day at the rubble of the twin towers were moving from a hunt for survivors to clearing away the massive devastation on the 16-acre site, Fire Commissioner Thomas von Essen said. 
"It's really happening in a normal kind of a transition that I think is acceptable to everybody and the best way for us to get this done," Von Essen said. 
Workers who had been sifting through debris by hand were bringing in more heavy equipment to move the twisted steel and crushed concrete remains of the city's tallest buildings, he told NBC's "Today" show. 
"So much of the concrete and everything else was vaporized or really crushed and pulverized that we need the heavy equipment to move some of the steel," he said. 
While experts say survival is still possible, Mayor Rudolph Giuliani said, "The experts have not dealt with a situation like this before, which is two hundred-story buildings that have been driven deep into the ground that are still partially on fire underground." 
Experienced forest firefighters joined rescue crews to help douse the subterranean blazes that persisted 10 days after the twin 110-story buildings were rammed by two hijacked planes and collapsed in terrifying heaps. 
Workers had hoped to find survivors inside voids within the rubble, but fire officials said the open spaces they had found were too hot from the blazes to have sustained life. 
Workers still combed through the rubble carefully, Giuliani said, in an effort to find human remains, at the least. 
But only 252 people have been confirmed dead, and of those, just 183 have been identified, he said. The list of the missing remained at 6,333 people, and 6,408 people were reported injured. 
Around the site of the disaster, rescue workers fought off feelings of dejection. 
"I think we all know we are not going to find anyone in there now," one firefighter said. "I pray we do, we all do, but we are losing hope. That thing came down so hard." 
Giuliani said a shift to recovery from rescue efforts would not be likely to come in an official announcement. 
"I don't think we'll have to do it that way. I think what will happen is over a period of time, the emphasis will change," he said. 
Saying that the chance of finding a survivor is "very, very small," he added, "The chance of recovering significant numbers of people who survived is impossible." 
No survivors have been found since Sept. 12, the day after the coordinated strikes at each of the Trade Center towers and the Pentagon outside Washington. A fourth hijacked airliner crashed in rural Pennsylvania. 
Throughout the surrounding financial district, where the towers were once unforgettable fixtures on the skyline, businesses and restaurants were reopening. 
"We are back, but it is very, very difficult. There is too much sadness, you can feel it all around," said office worker Carmen Montoya. 
At the New York Stock Exchange, which reopened on Monday after being closed for four days, investors dumped shares for a fifth straight day. Blue chips logged their biggest weekly loss since the Depression. 
On Friday night, some 400 anti-war protesters gathered under a heavy police presence in Times Square toting placards reading "Resist the War" and chanting, "No more victims, no more violence, no more war." 
As the protesters chanted, one vendor on a Times Square corner did a brisk business selling T-shirts for $10 emblazoned with the image of Osama bin Laden and the words "Dead Man Walking." Bin Laden is suspected by the United States of having been behind the attacks. 
In the first major sporting event in the city since the attacks, about 35,000 people chanting "USA" attended a Major League Baseball game between the New York Mets and Atlanta Braves. Mets players wore caps honoring the city's fire department, police and emergency services, the Port Authority police, and state court officers. 
More than 300 firefighters and emergency services workers were among those lost. 
Giuliani, a well-known fan of the Mets' crosstown rivals, the Yankees, attended the game and was greeted by fans' chants of "Rudy! Rudy! Rudy!" The mayor quipped that "things will be back to normal when they boo me again at Shea Stadium." 
Liza Minelli led the crowd in singing "New York, New York" during the seventh-inning stretch. 
Also on Friday night, performers from every corner of the entertainment world -- including Bruce Springsteen, Julia Roberts, U2 and Tom Hanks -- appeared in a two-hour televised benefit for victims of the attacks. 
Former Beatle Paul McCartney said he too was planning a concert to benefit New York firefighters. 
