The destruction of New York's iconic twin skyscrapers, the triumphant symbols of American financial and cultural hegemony, has horrified the western world.

Those transfixed by the television pictures will find it hard to forget the wrenching images of bodies hurtling from the sky in a vain attempt to escape a fireball, of firemen bravely tramping up flights of stairs to a certain death, or of ash-covered secretaries running shoeless from the steel towers collapsing behind them. Who will forget the heart-rending video footage of those in the top floors of Tower One waving handkerchiefs from blown-out windows, signalling to rescuers who would never come?

But for business in the capital city of Mammon, the time is not too soon to consider what shall be rebuilt, and how, and by whom.

Last week, with only a fraction of what is estimated at more than 5,000 bodies removed from the ruins, New York City officials announced plans for a "reconstruction commission" with powers to lead the recovery.

The City Council is to amend the city charter to give the commission "extraordinary powers to redo and rebuild and to do whatever is necessary", according to Peter Vallone, the council speaker and a contender for the Democratic nomination for mayor.

The commission is expected to be given powers to speed demolition and grant building permits, and possibly to condemn property, where necessary, for redevelopment.

Meanwhile, Federal money - about $20 billion (€21.6bn) - has already been earmarked for disaster recovery.

Larry Silverstein, president of Silverstein Properties, which had just purchased the World Trade Centre, said his company had a moral obligation to rebuild on the site. Yesterday, Mr Silverstein said: "There is not a doubt in my mind we would be seriously looking at building four towers 55-60 storeys in height."

He said the cost of construction for two 110-storey towers would be far greater than for four smaller towers.

Bernard Tschumi, the dean of Columbia University's architecture school, was dismissive of any suggestions that the site be set aside as a memorial: "Yes, there should be a place to mourn, but that shouldn't be the main thing. It must be a place looking to the future, not the past."

Terence Riley, architecture curator at the Museum of Modern Art, likened the destruction of the World Trade Centre to the Chicago fire of 1871.

Out of the ashes, he said, skyscrapers were born, changing the way cities have grown around the world. "We should build an even greater and more innovative skyscraper," Mr Riley urged.

Tony Malkin, president of property investment group W&M Properties - his grandfather was one of the builders of the Empire State Building - dismisses as "ludicrous" the idea that Manhattan can no longer be the US's core financial district.

"It's a self-selecting market," Mr Malkin says, noting that companies locate there because that is where they need to be in order to attract talent. He says New York is the mecca for highly trained, creative staff that drive the financial services and media industries.

Those businesses that can leave probably already have, he says, adding that high rents have shaken many tenants out. Ironically, he says, the destruction in Lower Manhattan comes at a time of falling demand for real estate.

According to data from Grubb & Ellis, property consultants, the amount of space withdrawn from the market as a result of the attack is slightly more than the total of available space in Manhattan.

About 15.5 million sq ft has been destroyed outright and a further 12m sq ft has been damaged.

This compares with 25.5m square feet of vacant Manhattan office space - only a small percentage of which is available in the large-floorplan format favoured by former WTC tenants. Besides this, a further 22m sq ft is available in New Jersey.

Jacques Gordon, head of research at Jones Lang LaSalle, says that even with modestly damaged buildings, reoccupation will take time.

The explosions had unleased toxic contents, including asbestos, from the inner core of the WTC towers. Surrounding buildings could not be reused until all traces of toxic dust had disappeared.

"There is a tremendous amount of re-building to do," according to Faith Hope Consolo, vice-chairman of Garrick-Aug Associates, a property consultancy specialising in retail assets.

"I don't think this is a one-year job. It will take years." But, she says, "it will be rebuilt. In New York, we are all survivors."