Torrential storms created more danger for rescue teams in Manhattan, covering the rubble in a sheen of rainwater and stirred up choking dust.
Heavy rain and high winds made the chances of finding survivors more remote, while inaccurate reports about police and firemen being found alive raised and then shattered hopes.
Digging amid the ruins of the World Trade Centre, which rescue teams have named "The Pit", was temporarily stopped after thunder and lightning broke in the early hours. Work remained slow as rain fell through yesterday morning.
Emergency workers had hoped that rain would clear the dust that was burning people's eyes and throats, but it only made matters worse and added to fears about the stability of buildings still standing.
About 1,000 firefighters, police, ambulance workers and volunteers have laboured since Tuesday to reach anyone trapped under the wreckage, but – as of yesterday afternoon – no one had been found alive since Wednesday.
Storms had been forecast, but rescuers had hoped the weather would stay away. When they broke at 1am, the operation had to be briefly called off. One volunteer, Richard Coppo, said: "The rain made the footing a little more dangerous. We hoped that maybe it would settle the dust and make things better, but it stirred it up." A rescue worker, Mike O'Hare, added: "It slowed us down a little bit. It affected the visibility."
Amid the chaos and confusion, hope seemed to be sometimes taking over from reality. There were reports that five New York City and five Port Authority police officers had been found alive, although trapped in an air pocket below ground.
One of the officers was said to have called his wife on a mobile phone to say he and others were trapped two levels below ground. One rescue worker was quoted as saying: "We've got 10 brothers down there alive. The woman was on the scene and talking to her husband on the cellphone."
Heartbreakingly for police and firefighters desperate to save some of the 400 of their colleagues who are officially missing, the city authorities later said the reports were untrue.
It was the same with five firemen who were reported to have been pulled from the rubble after being trapped since the towers imploded on Tuesday. Their survival had given hope to people involved in the operation and to New Yorkers still getting to grips with the catastrophe, but the city's fire department announced that the truth was that two firemen had fallen into a ditch during the operation and had been trapped for just a few hours.
There was no better news from Washington, where the operation at the devastated Pentagon building continued, having been hampered by a fire that broke out in the debris. Searchers found the "black box" flight data and cockpit voice recorders from the hijacked American Airlines plane that crashed into the military complex, but there were no new survivors.
The dispiriting news did not appear to dent the determination and patriotic defiance in New York City. Many firefighters at the disaster site pinned United States flags to the backs of their black uniforms while fire engines and emergency medical vans also flew huge Stars and Stripes.
They moved amid a landscape of devastation upon which four days of excavation have made little impact. More than 6,000 tons of debris have been removed from the scene so far to be transported to the Fresh Kills landfill on Staten Island, where it will be analysed by FBI officers and police officials. But, though cranes stationed among hills of rubble steadily swing loads of melted steel into a convoy of dump trucks, the size of the piles of wreckage seems to barely shrink.
Long chains of volunteers help to pass buckets of debris while all the time listening for any sound of a survivor. Yesterday, one chain of about 100 people stopped abruptly when a shout went up that a search dog had spotted something.
The workers lowered their buckets, turned and listened, but there was nothing to be heard. The volunteers at the front of the line picked up their buckets again and went back to work.
The stability of buildings that surrounded the twin towers of the World Trade Centre and that are still standing remain a concern. Liberty Plaza and Millennium Tower were both in danger of collapse and officials said that they have still to make a detailed assessment of the area.
Ted Beck, a structural engineer at the lower Manhattan site where the towers stood, said: "[We] have to take each building, each area of each building piece by piece to evaluate where the load path is coming from. And of course, make recommendations as far as what shoring has to be done temporarily [to] support what's up there."
One senior fireman who had pulled and crawled his way through to underground train tunnels at the very bottom of the devastation refused to give up hope.
"Time is of the essence," said Captain John Rhatigan. "There are plenty of voids underneath the building. There is plenty of hope. That is why people are digging here now.
"It is dangerous, but this is the career we have chosen and this is what we do. There always seems to be hope. There are opportunities still, even as a week goes by."
His determined optimism appeared to be borne out by continued reports of people using mobile phones to let friends or emergency services know they are alive. Hopes were again encouraged by reports that rescuers were trying to reach a woman heard tapping in the ruins. One policeman said: "Someone is tapping from below and they can't get to them. They are still alive. It sounds like she is alone, it sounds like she is all by herself."
Another man was thought to be using a mobile phone to send e-mails from underneath the remains of the north tower, but there was no confirmation he was there.
As one volunteer rescue worker, Lou Ferarro, put it: "We've heard rumours of people hearing knocking and such things as that but, from where we were, we don't know."
As the disappointments mounted, the operation is beginning to take its toll. Workers are finding that instead of saving people's lives they are discovering nothing but body parts.
Frank Terry, 34, found himself unable to continue after pulling the remains of a man's torso from the rubble. He took a break on a filthy ledge, drained and exhausted.
"I wasn't prepared for this. You can't get it out of your mind. You can't forget this," he muttered quietly, unable to take his eyes off the human remains.
Another rescue worker said he had found a liver, and others described being guided to corpses by the smell of decaying flesh.
Jason Rodriquez, 30, a highway construction worker from Baltimore who drove to New York to volunteer, could not stop his eyes filling with tears as he recounted what he had seen. "We found a woman folded in half. One of her thighs was completely missing. Her other leg had no foot."
Surveying the twisted mass of steel and concrete around him, now made slippery by the storms, he went on: "It's difficult to imagine that there might be people alive under this. But we can't give up on hope. That's all we have."Reuse content