US: For two hours yesterday we relived September 11th. Radios in taxis and shops crackled with reports of an explosion in downtown Manhattan. Fire engines raced through streets lined with frightened pedestrians.
New York TV stations abandoned their scheduled programmes to go to "Breaking News" and we watched in alarm the familiar pictures of bleeding and bandaged people sitting dazed on sidewalks as firemen raced into a stricken building.
It was all on a much smaller scale of course. The building where the explosion took place was a 10-storey commercial premises and there was no fire. Then after two hours the police said it was not a terrorist attack but most probably an accidental explosion in a boiler room.
It was by any standards a serious industrial accident which paralysed several blocks in Chelsea two miles north of ground zero. But it was not the return of al-Qaeda. Some 36 people were injured, according to police spokesman Mr Michael O'Looney.
St Vincent's Hospital where most of the injured victims from the World Trade Centre were taken - pictures of the missing still plaster the walls - went into "full disaster mode". Six of the injured were brought to St Vincent's in critical condition with head injuries, multiple fractures and severe burns. Another 14 were admitted to three other district hospitals.
New York has been extra jittery in the last two weeks because of warnings from the US Attorney General of the possibility of new attacks, and everyone feared the worst. At first it was thought that the 11.30 a.m. blast had occurred in the adjacent Apex Technical School but all students were evacuated safely.
Plumbers were working on the boiler under the Kaltech Industries Offices in the commercial building. Its brick facade fell into the street and some floors partially collapsed. Windows along 19th Street were blown out and several people were hit by flying glass. Technical student Scott Bonilla said the school shook before the blast. "They told us to rush out of the building. There was like an explosion and I ran out of there."
Ms April Sack in the Tonic Restaurant said the boom shook her building, and actor John Heffernan said "there was glass falling everywhere". Chelsea resident Bill Beek, who lived half a block away, said he heard a giant boom "like an airplane crashing". That was the worst thing, the thought that it was another plane.