By Peter Gould BBC News Online in New York

The first anniversary of 11 September finds many New Yorkers feeling apprehensive.

It is not just the possibility of a further attack that is causing concern, although many people feel it is only a matter of time before the terrorists return.

There is also the emotional impact of remembering one of the darkest days in the history of the city and the nation.

The past year has seen New Yorkers working their way through the trauma of mass bereavement.

The ceremony will be broadcast across the world

According to the latest estimates, 2,801 people died in the ruins of the World Trade Center.

For 12 months, the city has been attending funerals and memorial services, and listening to heartbreaking stories of loss.

It has cast a pall over the lives of New Yorkers, and there has scarcely been a day over the past year when they have not been reminded of 11 September.

Some of the bereaved families say they will be spending the day quietly, in acts of private remembrance.

Difficult milestone

They accept the need for public ceremonies, but they will be relieved when this particular milestone is passed.

Some of those who escaped from the World Trade Center say they now want to get back to something approaching normality. They will never forget lost friends, but they feel it is time to move on.

But first the city has to get through the anniversary.

Television networks gear up for the anniversary

Television networks have cleared their schedules, and although they are promising the anniversary will be covered sensitively, some parents say they will not let their children watch.

But while some people are uneasy about reawakening painful emotions, New York will come to a halt to remember its dead.

Before the ceremony, bands of pipes and drums will march through the city's five boroughs, converging on Ground Zero.

Silent remembrance

At 0846, the time the North Tower was struck, there will be a brief silence, and church bells will be rung.

There will also be moments of silence at 0903, the time the South Tower was hit, and at 0959 when it collapsed.

A fourth silence at 1029 will mark the moment when the North Tower fell, and then bells will once again ring out across the city.

New York remembers its dead

Former Mayor Rudy Giuliani will lead a reading of the names of all those who died, and the families of victims will lay flowers.

The acts of remembrance in New York will recall key moments in American history.

There will be a reading of extracts from the Declaration of Independence, made at the birth of the nation on 4 July 1776.

In a famous passage it states: "We hold these truths to be self evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness."

There will also be a reading of the Gettysburg Address - the speech delivered by Abraham Lincoln on a Civil War battlefield in 1863. It ends: "We here highly resolved that these dead shall not have died in vain, that this nation under God shall have a new birth of freedom, and that government of the people, by the people, for the people, shall not perish from the earth."

Candle-lighting

At sunset, an eternal flame will be lit in Battery Park, close to Ground Zero. There will be a reading from the "Four Freedoms", a speech delivered in 1941 by Franklin Delano Roosevelt.

He told Congress that he looked forward to a world based on four essential human freedoms: freedom of speech and expression, freedom of worship, freedom from want, and freedom from fear.

The ceremonies in and around Ground Zero will form the centrepiece of New York's acts of remembrance. People throughout the city are being urged to take part by lighting candles.

Peace protesters march along Broadway

While the nation is looking back to the events of a year ago, a debate is underway about President George W Bush's threat to remove Saddam Hussein from power.

Opinion polls show that a majority of Americans are in favour of intervention if it prevents Iraq acquiring nuclear weapons.

But there is a vocal minority opposed to military action, and at the weekend they held a peace march along Broadway.

So one year on, as the nation remembers the victims of 11 September, many New Yorkers are looking ahead with concern to what may now follow.

Click here to watch residents of New York give their views about September 11