"When your son dies it's not the sort of thing you can imagine - it's the worst of all your fears."

Those were the words of York dad Russell Marden whose 18-year-old son, Mark, died of sudden heart failure while he was studying at University in Canterbury. 

Mark, a former pupil at both Huntington primary and secondary schools, was in the first year of an occupational therapy degree at Canterbury Christchurch University and living in halls of residence. 

He had sent text messages to his family saying he felt under the weather one evening and went to bed that night, but didn't wake up.

Last week at an inquest Canterbury, his family - dad Russell, mum, Alison and 16-year-old sister Laura - heard Mark had died of acute myocarditis - a rare viral infection that can affect anyone. 

Russell, 47m, of Bracken Close, Huntington, said: "I can't pretend it's not been a hard time for our family.  We've got through it really by being together and supporting each other. 

"It's been absolutely awful. 

"As a parent it's pretty much the worst of all fears. 

"It's like the feeling you get in the pit of your stomach if your child goes missing in a shopping mall, but it won't go away. 

"Mark was a fun-loving lad, really likeable, and didn't really have a bad word to say about anybody." 

Mark had a very close group of friends at home and university who are now trying to raise funds in his memory for the charity CRY - Cardiac Risk in the Young, since his death in February. 

At Huntington Primary School last weekend, pupils braved the rain to raise £452.21 for the charity's national heart screening programme by taking part in a sponsored space hopper hop. 

Russell said: "I would like for some good to come out of something so tragic and if it stops another life being lost and another set of parents and friends going through what we have then so much the better." 

On July 15 Russell will be taking part in the CRY Heart of London Bridges sponsored walk which is 8km and takes in eight London Bridges. 

They walk hopes to raise £30,000 for CRY to raise awareness of conditions which can lead to young sudden cardiac death. 

Anyone wanting to sponsor him can log on to www.justgiving.co.uk/markmarden

Richard Tither, head of sixth form at Huntington School, said: "Mark was a lovely young man. 

"He was involved in lots of activities working with others that were less well off than himself. 

"He was hard working and always cheerful, always polite.  I know a lot of his friends have really been knocked back by what has happened." 

In February, The Press reported how a young York barman died suddenly, aged only 21. 

Jamie Tidswell, from Acomb, died after collapsing at home. 

A post-mortem examination revealed he had been struck down by viral myocarditis  and The Press set up an online book of condolence.  

What is Acute Myocarditis?

Acute Myocarditis is an inflammation of the muscular walls of the heart.  It may be due to a virus infection. 

Patients are usually relatively well and seldom present to hospital at an early stage. 

There have been sudden deaths associated with exceptional physical exertion in patients with viral illnesses.  Every week, eight apparently 'fit and healthy' young people die of undiagnosed heart conditions in the UK.