For people who knew Canning, it was a tragic end to an epic struggle. The 29-year old was introduced to heroin when he was an impressionable 15-year-old, living in Tallaght. His brother, too, was sucked into addiction and actually died of an overdose when Canning was younger.

The family moved to Leitrim, to flee the bad memories and the drug pushers.

But despite the constant love and support of his parents, Canning continued to struggle with his addiction to heroin.

"His mum and dad were always amazing, they would never have kicked him out or abandoned him, " said a close friend of Canning's, who went through a drug-rehabilitation programme with him.

"But for a long time, he just went his own way. He lived in America for a while, and nearly died there. It was a constant fight for him. It is for every addict."

Eventually, Canning enrolled in a rehab programme at Coolmine Rehabilitation Centre. From there, he joined the Homeless World Cup team, and was picked as the captain who would lead the team to Cape Town.

"He just had a way about him, like he was a natural leader, " said Canning's friend.

"He had a presence. He commanded respect instantly, and everyone just liked him. He was so easy to talk to, you had to like him. And even though he was a strong guy, had a strong personality, he could be so soft as well. He'd do anything for you."

This impression is backed up by the Homeless World Cup team organiser, Sean Kavanagh, who said that Canning was an "inspirational" team captain.

"His desire to achieve was evident to everyone, " said Kavanagh. "But he had a tender, loving side that was evident to anyone who saw him interact with the orphans he met in Africa."

Following the football trip to Africa, Canning passed the Junior Certificate, and he was due to start a football coaching course soon. According to his close friend, he had everything to look forward to.

"There was so much that he wanted to do, " he said. "He was talking about doing a sports science degree. I met him on the Thursday before he died, and he seemed fine. I don't think there was anything serious bothering him, I think it was just a weekend that went wrong. A bad decision, for whatever reason, and he died because of it."

That decision came in late January when Canning, who had been clean from heroin for a year, agreed to go out with a friend for the weekend.

At some stage he was offered heroin, and he accepted. But he wasn't used to the drugs and he lost his life.

For those people working with people addicted to drugs, it is sad but not shocking.

"When you're dealing with drugs, the danger of dying is always there, " said Kavanagh.

"We will remember him as a great friend and a loving son and brother. We'll miss him."

Canning's death coincides with the news that a health service dedicated to the homeless population of Dublin is going to be launched in May.

The Safety Net programme involves eight GPs and six primary-care nurses who will work out of health clinics in homeless facilities in the city.

The programme is fully computerised, allowing the GPs in the clinics to gain access to a patient's records, even if they had not attended that particular clinic in the past.

The scheme will enable doctors to run a preventative health service for the homeless for the first time. All homeless people on the northside of Dublin will also have access to the out-of-hours service DDoc, which in the past has only been available to patients holding a medical card.