A 21-year-old man killed in the Omagh bomb had been preparing to emigrate to the United States.

Mechanic Aiden Gallagher, 21, had been making plans to move to Boston with a friend.

His sister Cat Wilkinson revealed that his friend had moved over first and phoned their house on the day of Mr Gallagher's funeral with an update.

"He asked for Aiden and I said Aiden's dead, he said 'he's not, he couldn't be'," she said.

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"My mum always thinks what if Aiden had left, would he have been happier, at least he'd have been alive."

Ms Wilkinson heard the explosion from the family home before an agonising wait for news about Mr Gallagher.

"The longer you waited, the more you knew the news wasn't going to be good," she said.

"Everyone started arriving at our house, some of them had been in the town and some of them had been told that Aiden was in the town so they all came to our house, it was a wake without a body."

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Twenty years on when she looks at her children, she wonders whether Mr Gallagher would have his own family.

"I was 20 at the time, Aiden was 21, there was just 14 months between us, it was a big shock, we were always together," she said.

"All my school photographs are with him. At the time you hated it, but it's nice to look back on now.

"I just wonder would he be married, would he have a family, would my children have cousins.

"I see his friends pushing prams, walking with their wives, and I just wonder.

"But the pain is always there, you are just able to cope better with it."

Ms Wilkinson still keeps the pair of boots that her brother had bought in Omagh on the day of the bomb.

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"He went in to get a pair of jeans and a pair of boots, he got the boots first and went back to put them in the car, it was in the second shop he had got the jeans and that was beside the bomb car," she said.

"We keep them as a reminder, they were tin toed work boots. They have always been in the bag, sitting in the bottom of the wardrobe for the last 20 years."

Ms Wilkinson described Mr Gallagher, the only boy among her siblings, as the "golden child".

"He was the apple of my mother's eye, the two of them were inseparable," she said.

"Aiden was a mechanic, he had his own business, but he was always trying to push himself forward.

"He was like Arthur Daley (from the 1980s TV show Minders) because he was into cars, he was very much a character, definitely.

"The last car that he did was a complete overhaul of a 1967 Beetle, he gave it a complete renovation, parts had to be ordered in from Germany, this Beetle was the bane of his life. He absolutely hated it by the end of the project but he finished it.

"A few years after he died, the guy who he did the Beetle for decided to sell it to us and we still have it."

Ms Wilkinson said her work as director of Omagh Support and Self Help Group has helped her by helping others.

As well as working with victims of terrorism in Northern Ireland, the group has also reached out to the victims of the 7/7 bombings in London and the Manchester bombing, the Nice attacks among others.

"It's unreal to hear the stories and the similarities they have about issues such as truth and justice, access to support and financial support," she said.

"There are so many similarities, yet lessons don't seem to be learned."