NEW YORK -- New Yorkers will have to rely on their fabled resilience today as they begin to cope with the aftermath of the worst terrorist attack in the history of the United States.

New York Mayor Rudolph Giuliani said yesterday that he expects crews to begin the desperate search for survivors and the grim recovery of bodies from the attack on the World Trade Centre that reduced the city's most visible landmark to a massive pile of rubble.

Firefighters and rescue crews were prevented from searching for survivors yesterday because of extreme heat and the unstable condition of the smouldering wreckage. But throughout the day, cranes, bulldozers and other heavy equipment arrived to be ready when the all-clear is given.

No one venturing into the financial district today will get within a four-block radius of the World Trade Center site, where rescue teams will pull bodies from the ruins and move them to a makeshift morgue close by.

For today at least, little work is expected to be done in the city, a financial nerve centre not only for North America but worldwide.

In a televised news conference last night, Port Authority officials -- in charge of some of the city's main transportation hubs -- told New Yorkers that today "will not be a normal commuting day."

Officials said that depots such as bus stations and the ferry terminal are safe, but they did not say the depots are usable.

Manhattan's usually noisy, traffic-choked streets will be strangely still, with all major roads to the city closed, businesses shut and many people staying home.

Last night, train and subway lines would take passengers only a limited distance into Manhattan. Officials gave no indication when the transportation routes would become fully operational. However, they said they will not allow pedestrian or other traffic south of 14th Street, an area which encompasses New York University, Wall Street and the trendy residential areas Greenwich Village and Soho.

Residents of the nearby Tribeca area, prohibited from returning to their lofts last night, will try to get home today.

Kevin McCarthy, a banker whose building is one block away from the World Trade Center site, said he was told by his supervisor not to come to work for a few days. "He said, 'We'll get back to you in a couple of days.' "

Mr. McCarthy and his colleagues had watched from their windows as the hijacked airliners slammed into the trade-centre towers.

Nina O'Relly, a 29-year-old Canadian, said she wasn't sure she would want to go into Manhattan from her home in suburban Scarsdale.

"When I first moved here, I thought it was such a target. But to have it happen is simply incredible. I have no idea how life is going to be after this."

Mr. Giuliani told New Yorkers and commuters that if they feel they need today off to comfort loved ones, do so.

Stores were locked yesterday after the attack, and managers will reopen at their discretion. People trying to buy goods or conduct personal banking may be out of luck.

Mr. Giuliani warned people he called "gougers" -- anyone who would exploit the situation by charging inflated prices for food and water -- that they would face police action if caught.

Although the mood immediately after the attacks was of shock, anger developed later. The area's K-Mart stores will open today, but as a precaution will not sell guns and ammunition, officials said yesterday.

U.S. President George W. Bush declared the city a major disaster area yesterday, triggering federal aid for people and businesses recovering from the attacks. Residents and business owners can begin the disaster-application process today.

Mr. Giuliani encouraged city residents to give blood first thing today. Shipments of blood are coming to the city from New Brunswick, according to New York City television reports.

Telephone lines in the city were down last night, and it was unclear when service would be restored.

New Yorkers in the surrounding burroughs, as well, were dealing with shock from the attack. The Roman Catholic school district said its schools would not open today.