British relatives: Once they see the wreckage, the truth hits hard

"We fell like we have left him behind in the rubble – like we were near to him and had to go away again," said Pauline Berkeley as, once more, she replayed in her mind her son's last resting place.

Two weeks on, the arc lights and the pall of smoke above the ruins of the World Trade Centre remain the first and abiding memory for Mrs Berkeley after returning home from New York.

The 64-year-old retired nursing auxiliary, whose son, Graham, was on board United Airlines flight 175, was one of hundreds of Britons still trying to comprehend the horror.

Her feelings are typical of the emotions felt by hundreds of mourners unlikely ever to have the comfort of a body to bury from the wasteland of ground zero. For them, the conventional process of mourning has been replaced by an ebb and flow of grief and confusion.

One group of bereavement counsellors returning to Heathrow from New York yesterday described just part of the emotions being felt by those who have lost loved ones: "furious", "traumatised", "strong", "denying", "hopeful", "sobbing".

Fighting jet lag and camera lights in a conference at the airport, the volunteers for Cruse Bereavement Care said many Britons had come with hopes of finding missing husbands, daughters, nieces or cousins.

But, as they visited the scene bearing bouquets of flowers, the realisation had dawned that it was all but impossible for anyone to emerge alive.

Gwen Aaron, 57, who works for the charity in north Wales, said: "At the site, most just stood quietly or stood weeping. They had to keep moving along because of the crowd but they left their flowers.

"There were those who had arrived believing that their relatives may still be alive. But I think the enormity of the wreckage more than anything brought it home that their loved one wasn't coming back." But for many, say the experts, the cruel and abrupt nature of their bereavement means they have not yet even begun to let go of the idea that their loved ones are still alive.

Dr Arthur O'Hara, who is leading a second Cruse team still in New York, said: "Many are still in shock and have not yet reached a point where they are ready to move forward in the process of grieving.

"Returning home, coming to terms with the finality of their loss will be very difficult for them for weeks, months and years."

Bound by a confidentiality to those they had sometimes accompanied or offered a comforting arm, the counsellors could not reveal the names of the 80 British mourners.

But there were some telling snapshots of the private trauma of the group – already the subject of intense and sometimes intrusive media interest.

While most families were so shocked that only one or two members made the state- funded journey to America, one gathered 13 relatives who felt they had to come to see the devastation together.

There was another family – two parents and a bereaved wife – who were so intent on "being strong" for each other that one of them felt she could only come to a stranger to express her true feelings.

Others have had a desire to "offload", to rail and rant against everyone and anyone who may have been responsible – either by hijacking, negligence or chance.

Mrs Berkeley, who returned with her husband, Charles, 69, to their home in Shrewsbury on Monday, had flown to New York knowing that her son, an e- commerce executive, was dead. The couple watched the attacks on television believing that Graham, who lived in Boston, was flying to Amsterdam on a business trip he had told them about days earlier.

Then there was a phone call at about 10pm from United Airlines, telling them he had been on flight 175 to Boston, which hit the south tower.

But Mrs Berkeley said her early reconciliation to the fact that her son was dead had not eased the pain of her grief. She said: "We didn't want to go down to the scene, to ground zero but, on the plane, we saw the site from the air – you could see the lights, the smoke and the dust where the towers were.

"Being in New York made us feel closer to Graham. We knew that everybody was grieving for somebody who was there. But then we had to leave.

"It feels like we have left him behind there and we have to come home to mourn. I keep seeing in my mind the scene and the moment of the crash. It isn't easy. It is driving me mad."

The loss of about 200 Britons has begun to be quantified by the public as the names and photographs of 57 missing nationals have been published.

They are known by their last phone calls home; the heroic attempts of some to evacuate colleagues; their jobs as security advisers, stockbrokers, lawyers; their pregnant wives or recent engagements.

But, for their relatives, the greatest obstacle is that, all too often, nothing remains. The heat of the fires vaporised many bodies while the tales of scattered body parts being found are now all too familiar.

Patrick Shannon, a Cruse director, said: "The absence of a body or mortal remains is very difficult. There are things that can be done – a memorial service, a visit to the place of death – to ease that loss.

"A violent death is always very difficult to deal with. Our experience of events such as Omagh, Hillsborough, Zeebrugge, Bradford, Piper Alpha, King's Cross shows that."

In a disaster in which 1,500 children have been bereaved at one firm alone, Cantor Fitzgerald, where 700 staff are missing, the task of explaining a death to a youngster is hardest.

Under such circumstances, perhaps one would expect the victims' families to be talking of vengeance, the counsellors were asked.

The answer was disarming: Revenge? No. Not one person talked of revenge. They were thinking about other things.