The price tag of the terrorist attacks on the World Trade Center will be nearly $40 billion, an early estimate of what it will cost to remove debris, pay overtime and rebuild subways and skyscrapers, officials say.

Cleaning up the estimated 1.2 million tons of rubble will cost $7 billion alone and take up to a year to complete, officials said Friday in providing rough cost estimates of the destruction left when hijacked airliners obliterated the trade center.

"It's probably too early anyway, and no one can really say what the final costs will come to," said Kenneth Golding, a consultant who had come to see the site Friday night. "Also, it seems demeaning to try and put a dollar value on what happened."

U.S. Senate aides said Friday that government officials are looking at a price tag of $39 billion, which includes about $8.2 billion for rebuilding the trade center. But they said no decision had been made whether to rebuild the complex.

The costs also include $4.1 billion for repairing and improving subways and $3.6 billion in overtime and other associated costs for police, firefighters and other city workers.

Crews began demolishing the remains of the adjacent World Trade Center 4 building damaged by the collapse, crashing a wrecking ball through its roof early Saturday.

The building, which included a shopping concourse, was partially collapsed by the millions of pounds of rubble that fell after the attacks.

Kathleen Hart walked past crews working at the site late Friday and said it was too early to talk about rebuilding.

"The attack is still too fresh in people's minds, and the fear of the additional terrorist attacks remains," said Hart, 28, of New York. "I think it's premature right now."

As debris continued to be removed from ground zero, mourning for victims continued. At least 16 funerals or memorial services were scheduled Saturday around the metropolitan area.

The mayor has already warned that the bodies of some of the 5,960 missing victims may never be found. As of Friday, 306 bodies had been recovered from the rubble.

A city consultant said Friday that officials were on the verge of announcing "this is not a rescue operation anymore."

Once the rescue workers pull back, heavy-duty excavation equipment will be brought in, said Mark Loizeaux of Controlled Demolition Inc. The remaining workers will be trained to spot human remains and remove them "with the maximum possible dignity," he said.

Removing the debris is not without controversy. Police said Friday that some scrap metal may have been diverted to mob-controlled businesses rather than the Staten Island dump where investigators are examining the rubble for clues and DNA. A grand jury is investigating.

The traffic jams of earlier in the week were eased Friday by restrictions on single-occupant cars headed into Manhattan. Cars with solo drivers were barred from entering Manhattan via certain bridges and tunnels from 6 a.m. to noon.

"It seems to me that it worked, and it worked well," Mayor Rudolph Giuliani said, adding that mass transit ridership appeared higher.

Traffic for the evening rush hour was helped when the Holland Tunnel — closed since the attack — was reopened to outbound traffic on Friday afternoon. The traffic restrictions were not scheduled to be in effect this weekend.