Like many young men of his age, 33-year-old Kevin Smart enjoyed a flourishing career, a settled home life and was making plans for a future with his long-term partner.

On one September afternoon last year, however, the fit and healthy business analyst went out for a routine jog around Rickmansworth and never returned to his Broughton Way home. 

Kevin, who jogged the same five mile route at least twice a week, collapsed and died in the street when his heart stopped beating - one of the eight UK adults to die each week from the undetectable, undiagnosed Sudden Arrhythmic Death Syndrome (SADS). 

His devastated family now want to honour his memory by sparing others the devastation of the sudden death of a loved one; raising money for the charity Cardiac Risk in the Young (CRY) and promoting a screening programme. 

He didn't go to work that day because there was a train strike on," explains mum Debbie from her Loudwater home. 

"He decided it would be easier to work from home.  I spoke to him at about 1pm and he was fine.  We were all due to go on holiday together in Florida.  He was looking forward to it and happy in his life. 

"All we know about what happened next is that he went out running at about 5.30pm and didn't come back.  It was such a shock to us." 

Last Sunday the family joined hundreds of others for an emotional eight-kilometre fundraising walk across eight of London's most iconic bridges; a chance to promote a common cause and share their experiences. 

"Between us we wanted to do something proactive to help the charity," added Mrs Smart. 

"Obviously it's too late to help Kevin but if we can do something to help other people, then it will all be worthwhile.  The charity wants to provide access to screening for young people - particularly those involved in regular sporting activity. 

"It's awful to think of another family going through what we went through." 

After raising more than £3,000 in sponsorship money the family, including Kevin's girlfriend Natalie, are now setting their sights on more adventurous fundraising ploys. 

"We've thought about doing some longer runs and walks," explains sister Lynn.  "We've even discussed a parachute jump. 

"We know Kevin would be laughing at us if he could hear us now because that was what he was like - he was a real joker.  He was always the first at a party and the last to leave. 

"He was a great person to be around and will be missed by everybody."