Moments after this photograph was taken, the red car exploded and Omagh changed forever. Today the anger still hangs heavy in the town as it remembers its dead

Much has changed in 10 years. The clothes, the haircuts, the style of glasses like those on Gonzalo Cavedo's face, the shape of cars like the Vauxhall Cavalier parked behind him. The differences are often slight, but pronounced enough to place the whole scene that little bit in the past.

Much more changed in a moment. A short time after this picture was taken (by a camera that was later recovered from the rubble), the quietly bustling street churned into confusion as people responded to a bomb alert, evacuating nearby shops and moving to what was assumed to be a place of safety.

Confusion, then chaos and carnage. The 500lbs bomb in the boot of the Cavalier, made up mainly of fertiliser soaked in fuel oil, exploded. It was a few minutes after three o'clock on Saturday, August 15, 1998.

The blast obliterated the car, opening a crater in the street and sending thousands of bits of shrapnel and debris through the people crowded into the street. Getting hit by it, one survivor said later, was like being stung in hundreds of places at once. Flesh burned.

Many of those who lived through it, or came upon the scene immediately afterwards, repeat the same awful memory: blood literally flowed down the street.

This was Omagh, where hundreds and hundreds of lives were transformed in that awful instant. Twenty-nine bodies,

dead or dying, were carried away from that street. Spanish tourists – and travelling companions of Gonzalo Cavedo – Racio Abad Ramos and Fernando Blasco Baselga were among them. So were children on a summer day trip from Donegal. Avril Monaghan's body contained her unborn twins.

Mercifully, Senor Cavedo and his young friend survived.

Scores were injured, hundreds more emotionally scarred by the loss of their loved ones, the damage inflicted on them, or simply because they witnessed the grossest example of inhumanity the Troubles had seen.

At a time when Northern Ireland was supposed to be moving from conflict to peace — at a time when Northern Ireland was moving that way — the past stepped forward to ravage the hope.

Dissident republicans from the Real IRA set off the bomb as part of a campaign to disrupt the peace process. It failed.

Today, Omagh tries to mark that black day from the distance of a decade. The town's memorial garden opened close to the location of the bombing, with a glass monument at the same location where the car bomb was parked by two men exactly 10 years ago this afternoon.

The ceremony was due to open with music by the Omagh Waterford Peace Choir and an introductory greeting in English, Irish and Spanish.

A call to remembrance and minute’s silence was planned for 3.10pm, the time the bomb exploded. Then the names of the victims who lost their lives on August 15, 1998 were due to be read out.

Today's hour-long service was preceded by disagreements, including objections to the design of the memorial, which will reflect light from the garden to the glass plinth.

Some objections ran so deep that some of the bereaved families will hold a separate service on Sunday.

Omagh Council said today's service would be “reflective and reverential, but positive, optimistic and forward looking”.

They said that to fail to hold a service “would be to admit that those who planted the device in Omagh that day have been victorious”.

“The attack was indiscriminate, unprovoked and brutal.

“The attack may have wrecked the town and killed and maimed many people but we have rebuilt our town, we remember our dead in a reverent way and we continue to support our injured and traumatised.”

The years since the bomb have seen some pains lessen, some intensify, and new wounds open.

The failure to catch the killers — from the deep flaws in the initial investigation, to the disturbing end to last year's murder trial — has been deeply frustrating for many of those directly affected.

A civil case against men blamed for the attack could finish this year, but it seems unlikely to bring complete closure.

The returned focus on Omagh that came with the tenth anniversary brought along a powerful mix of emotions.

Much of it comes from seeing how the many young people injured in the bombing have rebuilt and repaired their lives.

Claire Gallagher, who was blinded at 15, is one. Claire remembers what it is like to see. She told a powerful BBC documentary last night that she remembers colours and shapes and the faces of her loved ones.

Those are memories. The actual images have been taken from her forever, but she refuses to be buried by her injuries. She has become a counsellor for others who have lost or are losing their sight.

“Everybody has their way of coping, and my way of coping is to get on with it,” she said.

As have many others, quietly getting on with their lives. That is inspiring but also underlines the terrible cost of Omagh – the lost potential of each of the lives destroyed or damaged, the ones who have never had the chance to fight back, and to mark the passing years.