Donations are flooding into the fundraising page of a 23-year-old man who died after collapsing during a marathon.
Sam Harper Brighouse, from London, is believed to have suffered a cardiac arrest at about the 16-mile mark of the Brighton Marathon on Sunday.
Attempts were made by medical staff, paramedics and an off-duty police officer to resuscitate him before he was taken to hospital where he underwent surgery, but he died a short time later.
Hundreds of people have made donations to his justgiving.com page with the total approaching the £5,000 mark - well above his intended fundraising target of £500.
His site states that he had embarked on the challenge to raise money for the Arms Around The Child charity which supports Aids orphans. He wrote: "I'm running, jogging, crawling the brighton marathon for Arms Around The Child (UK) (formerly KCA UK) because I am want to raise money for a good cause."
A spokesman for organisers of the marathon said: "It is with regret that we can confirm that a competitor collapsed and later died competing in the Brighton Marathon. Despite receiving immediate attention, the runner was later declared dead at the Royal Sussex County Hospital."
Mr Harper Brighouse's father Richard, 50, told the Evening Standard that his family was "mystified" as his son had been "as fit as a fiddle".
He said the family went to watch the marathon and followed Mr Harper Brighouse's progress using a GPS tracker, but it stopped about half-way round.
He said: "He loved sport. He trained really hard and was as fit as a fiddle. We are mystified, he has always been into sports like football and basketball and was very healthy. We thought the tracker had failed but then received a call at the finishing line saying he had collapsed. We just cannot believe it. We are devastated."
The paper reported that Mr Harper Brighouse, a biology graduate, had just completed a three-month internship at drum and bass record label Hospital Records and hoped to work as a record producer. His father said: "He was a caring, loving boy with no bad side to him. He was a really nice, straightforward guy."