Ceremonies were to be held in New York and across the United States early this morning to mark the fourth anniversary of the September 11, 2001, attacks amid deepening controversy over the redevelopment of the site that once held the World Trade Centre.
The empty pit that Ground Zero has become remains a place of crumbling cement and weeds clinging to ledges and crannies as squabbles about priorities for the site remain unsettled.
Politicians have tried to put a brave face on the absence of progress.
Most significant has been the hold-up in construction of the signature 541m Freedom Tower. It has been delayed by disputes among architects and a recent re-drafting of its blueprint to make it less vulnerable to attacks.
The problems were accepted for the first time last week by mayor Michael Bloomberg. Although another US$10 billion ($14.1 billion) would be spent on work at Ground Zero in the next six months, he said, more might be necessary. "Given the magnitude of the project, the progress probably wasn't adequate."
While all sides seem to have settled on the Freedom Tower design and where it will rise from, a new and emotional dispute has opened over plans for a cultural centre that will incorporate the International Freedom Centre museum and an art gallery, the Drawing Centre.
Some families of victims have launched a campaign to have the Drawing Centre excluded, claiming that it plans to show artwork not directly related to the terror attacks.
Officials have said they will offer exhibits showing other great moments of sacrifice and loss in American history. Some families complain that such exhibits are inappropriate and would detract from the main reason to visit the site to ponder 9/11 and those who died there.
Debra Burlingame, whose brother was a pilot on the plane that struck the Pentagon, has formed a group called "Take Back the Memorial". She and some supporters have voiced suspicions that some exhibits in the centre could be un-American. The visiting public would "come to see 9/11", she wrote in the Wall Street Journal, but instead "will be given a high-tech, multimedia tutorial about man's inhumanity to man, from Native American genocide to ... the Soviet gulags and beyond".
With moments of silence planned for this morning to coincide with the times that the two planes struck the Twin Towers, the controversies will be put aside at least for the day.
Emotional closure is still absent for so many who either have not been able to bury any identified remains of their lost ones, some incinerated by the impact of the two airliners on the towers, or remain in the dark as to exactly what befell them.
Just last Wednesday, the family of New York fireman Gerald Baptiste were finally able to take his remains, identified at last, to St Patrick's Cathedral for a funeral.
* Americans remember the fears and uncertainty and confusion of that terrible morning. But above all, we remember the resolve of our nation to defend our freedom, rebuild a wounded city, and care for our neighbours in need.
President George W. Bush.
* We are living that part of history. We learn from the past.
Ailyn Alonso, of Maryland, at the site where one of the hijacked planes hit the Pentagon.
* It's the only way to recapture the worst day in the history of our city and the best day in the history of our city.
Former New York mayor Rudolph Giuliani.
* My dad always used to say, 'Get over it, get on with it. Stop crying.' I can't bring him back. He would kill me if I didn't get on with my life.
Erica Basnicki, from Toronto, who lost her father in the attacks.