People may be nervous of them now, but companies need central locations

IN THE chaotic, dust-choked aftermath of last week's New York atrocity, one fleeing survivor screamed at a television camera that this was her second escape; that she had been in the World Trade Centre when it was bombed in 1993.

Many in the US and elsewhere hope that the twin towers will be rebuilt, that the murderers' supporters are not granted the victory of seeing empty city blocks turned into memorial parks.

It is an admirable response, recalling the resolution of Londoners and residents of other British cities who went back to work after IRA bombings and who repeatedly rebuilt shattered workplaces and shopping malls.

But the human toll of last week's attacks exceeds anything that has gone before. Who could blame those who would prefer not to return to a rebuilt World Trade Centre or who now have qualms about working in prominent skyscrapers anywhere?

Already people are asking why we need such large workplaces and whether, in an age of wireless communication, it is necessary to gather so many employees in one place.

It is a question many believe has already been answered. The end of the office never happened. John Seely Brown and Paul Duguid noted in The Social Life of Information, published last year, that in 1998 the US office vacancy rate dropped to single digits for the first time since 1981, in spite of an increase in new building.

We are social animals. People work from home more than they used to but few do it every day.

Companies prefer clusters because that is where they find the talent, the ideas and the industry intelligence. Once an industry gathers in one place, so do its financiers and support services.

Successful cities do not have to build upwards. London and Paris remained relatively low-rise centres. But cities that run out of space have little option but to build skyscrapers. They were the answer for the island of Manhattan and, until last week's attack, were seen as the salvation of the square mile of the City of London, threatened both by Canary Wharf and competing centres.

Ken Livingstone, London's mayor, said in May that London would need higher-density buildings if it wanted to remain competitive. There are proposals for several new tall buildings, including a 66-floor structure, Europe's tallest, at London Bridge station. The proposed building's creator, Italian architect Renzo Piano, describes his design as being like a "shard of glass".

What are the chances now of new skyscrapers being built? "It's impossible at this stage to answer that," says Sir Stuart Lipton, CE of property group Stanhope, and chairman of the Commission for Architecture and the Built Environment. The economic arguments in favour of companies gathering their employees in one building remain strong.

People will attempt to return to normality this week. Those who work in skyscrapers will take their lifts to the usual floor. They will worry about their safety. As long as terrorists remain active, a city that has been attacked never entirely returns to normal.

But at times of anger, grief and fear, the need to be among familiar faces becomes stronger than ever. Financial Times