A fine soot occasionally drifts down, leaving black specks everywhere, and a dank odour of smouldering debris comes and goes, according to the whims of the breeze. Three weeks after the destruction of the World Trade Centre, and with smoke still seeping from the ruins, the southern tip of Manhattan is an unpleasant, depressing place.
On Friday the burnt rubber smell was so bad in Wall Street that it penetrated the New York Stock Exchange floor. People left town early, and one Broad Street firm sent its employees home at lunch-time.
The heart of downtown Manhattan has become the world's biggest search and recovery site. Day and night, huge cranes inch forward on tank treads to lift steel girders twisted beyond the imagination of experienced salvage experts.
Yellow Mazzocchi diggers climb high on the mountain of rubble like mechanical dinosaurs to open new avenues into the wreckage. More bodies are being found every day as they dig deeper, 50 on Monday alone, but still only a fraction of the 5,219 people officially missing or dead.
While the rest of the city tries to get back to normal, it is becoming more and more evident that it will be many months before the recovery work on and around the twin towers site is scaled back. Apart from the constant reminders of the horror of September 11th, the disruption is getting to people. They have to endure police and National Guard security checks for many blocks around the site.
Some 8,000 Battery Park city residents are still unable to return to their homes, part of the biggest displacement of New York people since the cholera outbreaks of the 19th century.
The spirit of tolerance and understanding in the days after the attacks has been replaced with frustration. A meeting of several hundred residents with a mayor's aide last week ended in an angry walkout.
The "militarised" areas and many districts to the north face a dismal future. Shops, art galleries and restaurants will close for business in the months ahead, adding to the bleakness of a part of the city which has already lost its biggest shopping mall and restaurant complex under the twin towers.
No one wants to come downtown for shopping or socialising any more. Robert de Niro's fashionable Tribeca Grill restaurant, six blocks along Greenwich Street from where a 10-story high mountain of rubble blocks the road, reopened on September 24th after 13 days, but hardly anyone came.
The city authorities are trying hard to restore some semblance of normality. The circle of police and National Guard checkpoints has contracted. Limited traffic has been allowed on streets east of Broadway, and Manhattan Community College, Stuyvesant High and two primary schools on the west side are reopening this week.
Nevertheless it is impossible to take a taxi or private car to within half a mile of Battery Park City and Wall Street traders and brokers who were used to driving alone into lower Manhattan now face a ban on single-occupant cars using bridges or tunnels.
The city's subways can get people close to their work but downtown's busiest underground intersection which many financial workers used is utterly destroyed. It will be years before engineers can restore service in the collapsed subways under the World Trade Centre.
Almost 600 feet of line in the numbers one and nine subway tunnels lie under millions of tons of rubble and steel, and the beams in other tunnels are sagging dangerously, closing stretches of the N and R lines.
Where subway steel supports have collapsed, the roads and pavements above are in danger of subsidence.
Repairs and reconstruction to the disaster site mean disruption over a much wider area. Ready-made concrete for example comes from New Jersey and because of traffic restrictions the trucks with their revolving drums cannot reach southern Manhattan in the one-two hours before the mix is spoiled. A new concrete factory is to therefore be constructed on the Hudson River promenade on the west side, already despoiled by a floating dock working as a trash transfer station for barges to convey wreckage to the Fresh Kills landfill at Staten Island.
After the initial personal trauma, many financial workers and residents are taking stock and making hard decisions about whether they want to live and work in the district anymore, especially those who lost friends and colleagues.
Some are sceptical about getting back to normal any time in the next year or so. "Normal will become what we have now," said a financial analyst who is moving to New Jersey.
It is not a full-scale flight, but downtown Manhattan is undoubtedly haemorrhaging. It is losing many of the people who helped make it a vibrant, desirable community, and financial institutions and offices are taking note of their sense of isolation.
A number are looking to look for more attractive locations. Indeed the out-of-Manhattan trend was started years ago when big asset management offices relocated to Greenwich, Connecticut and this may very well accelerate.
"New York is too tense for me," said a woman employee at the undamaged Mercantile Marine offices, explaining why she is determined to move. "Down here its noisy and odorous, and you worry all the time. Who needs that?"
