Three years ago, Marie Watts discovered her 17-year-old son, Dean Grey, had inexplicably died at the family home in Parkfields, Roydon.
"I took him a cup of tea like I did every morning. His whole body was frozen. His tummy was still. I knew he was dead.
"I loved him so, so much," she said.
"I didn't want anyone to take him away from me."
Dean was a fit and healthy teenager who had spent the previous day with a friend. that evening he complained of a headache and, after saying goodnight to his mum, he went to bed. That was the last time Marie (38) saw her son alive.
Her partner Mark tried to resuscitate Dean before paramedics arrived and took him to Princess Alexandra Hospital (PAH). Four separate attempts were made to revive him, but in vain.
Dean grew up and went to school in Harlow before he moved to Roydon. He worked part-time at Pizza Hut and studied graphic design.
He dreamt of joining the Royal Air Force and a new life beckoned before tragedy struck.
"He had everything planned out," she said.
"Two weeks before Dean died, you could have never seen another boy more happy."
What made the situation more difficult for Marie was that it took medical experts a month to determine her son had died as a result of Sudden Adult Death Syndrome, which is likened to irregularities of the electrical impulses that upset the natural rhythm of the heart.
"During that month, I was completely numb," said Marie.
"When they told me, I wouldn't accept it."
The inquest held six months later determined he had not taken drugs nor consumed alcohol and there was no indication of foul play.
Pathologist Jolanta McKenzie suggested a heart problem but gave the official cause of death as unascertained, leading to the coroner's verdict of natural causes.
This sent Marie into further depths of despair. As far as she was concerned her son had died for no reason.
"I couldn't come out of my front door," she said.
"I couldn't work out how the world carried on while my son's not here. I was going to the doctors thinking there was something wrong with me."
But during the past year the fog has slowly lifted and Marie began to research further into SADS and how common it is becoming.
According to the Department of Health, as many as 400 apparently healthy young people die each year from SADS – that's an average of eight a week.
the main conditions which cause SADS are hypertrophic and dilated cardiomyopathy – which both affect the muscular walls of the heart. It can also be caused by disorders affecting the electrical conduction system of the heart which can led to arrhythmias, an abnormal heartbeat rhythm.
but the good news is that heart problems in young people can be detected and Marie is now determined to wrestle some good from her tragedy by helping others who are at risk of dying in similar circumstances.
Meeting Dean's friend Chloe Gifford at his grave in Parndon Wood Crematorium one day helped boost her efforts and the pair have struck up a close friendship and set about planning two fundraising events.
Chloe (19) said: "He was a brilliant friend. I was in with a group of lads and one o f them called me to say he died. I really couldn't believe it – I thought it was a joke. I couldn't get my head around it.
"I've been spending so much time with Marie. In a way it's been a good thing that I'm coming to terms with his death by doing what I'm doing."
through raising money for the SADS UK and Cardiac Risk in the Young charities, the pair hope to donate heart monitoring equipment worth £3,000 to PAH to help detect cardiac irregularities in the young.
On Sunday, they are embarking on a sponsored walk from Roydon to Ware, along the river path Den himself used to take on his bicycle.
then, on November 10, a charity party will be thrown in Harlow, based around the theme of gangsters after Dean's favourite film, The Godfather.
It will also be a belated celebration of what would have been his 21st birthday last month.
Representatives of both charities will be at the party to provide information about their work and to advise on the syndrome.
Marie has started to write a book about their life together, but her ultimate goal is to reach out to young people to, in her words, "urge them not to waste their lives" because her son's was over so quickly.
To this end, she has started to train as a youth worker.
