Relatives in Ground Zero procession

Relatives of those who died in the September 11 terror attacks will remember their loved ones as they descend a ramp into Ground Zero this week.

Family members will walk in single file to the lowest level of the site where they will be able to lay flowers and pay their respects.

The procession was a compromise move following safety fears over the use of the site in Lower Manhattan.

Of the 2,973 people killed five years ago when terrorists hijacked aircraft and caused horrific destruction by flying them into New York’s World Trade Centre and the Pentagon, 67 were British.

The ceremony will pause four times for silence, twice to mark the time when each plane hit the Twin Towers, and twice at the time when each tower fell.

Those who responded to the terrorist attacks and helped with the recovery efforts will read the names of the victims.

As the anniversary drew near, al-Qaida leader Osama bin Laden urged the American people to “embrace Islam” in his first video for almost three years.

For the first time, one of New York’s television stations originally opted not to broadcast the full reading of the 2,749 names killed in the attacks on the World Trade Centre.

W-ABC TV later changed its decision not to screen the reading of the names, often the most emotional part of the service, following the reaction of victims’ families.

Lee Ielpi, president of the September 11 Families Association, choked back tears as he talked about how he lost his firefighter son Jonathan, 29, who was married with two children, six years ago.

“No matter how many times you say it, it still has this effect on you,” he said.

“It stays forever.”

His son’s ripped jacket and firefighters’ helmet – one of just 12 recovered from the debris following the towers’ collapse – are on show at the WTC Tribute Centre.

Hundreds of “missing” posters line the centre’s walls along with more than 1,200 photographs provided by relatives of their loved ones.

Later on Tuesday, relatives of British victims will attend a separate commemoration at the British Memorial Garden in New York’s Hanover Square, around half a mile from the World Trade Centre site.

An honour guard of British police officers will fly in for the free community concert and ceremony to commemorate the sixth anniversary.

On September 11, 2001, a total of 266 passengers and crew were on board the four jets, two of which hit the World Trade Centre towers, while one crashed near the Pentagon in Washington DC and the other came down near Pittsburgh.

In a measure of the carnage on the ground, five hours after the attacks there were no estimates of the overall death toll.

Nightmarish images of people jumping from the Twin Towers were sent around the world as New York City Mayor Rudy Giuliani urged people to be calm and to walk out of Lower Manhattan.

World travel was thrown into chaos. Many US-bound flights had already left the UK when American officials closed all US airports.

Thousands of passengers, including the Duke of York, were diverted, or turned round mid-Atlantic.

In London, workers left some high-profile buildings amid concern they could be the next target.

The London Stock Exchange, the Lloyds building, Canary Wharf and the NatWest Tower in central London were among those with workers streaming out as panic spread across the world.

Armed police were sent to the US Embassy in London’s Grosvenor Square and security was also stepped up at British military bases.

But in the West Bank and Gaza, thousands of Palestinians celebrated the terror attacks chanting “God is Great” and distributing sweets to passers-by, even as their leader, Yasser Arafat, said he was horrified.