Teenager Stephen Sutton, who dedicated his life to spreading happiness and inspiring others, has lost his cancer fight, aged just 19.
Stephen, from Burntwood, Staffordshire, was diagnosed with incurable metastatic bowel cancer when he was 15. But despite the devastating prognosis, he remained determined to experience life - writing a 46-point bucket list of adventures to complete along the way.
ITV News Correspondent Rupert Evelyn reports:
From hugging an elephant to crowd-surfing in a dinghy, from banging a drum at Wembley to skydiving - the formidable teen continued to live life to the full.
That spirit inspired other celebrities to join him as he aimed to raise £10,000 for the Teenage Cancer Trust.
But when the teenager posted on his Facebook page what he believed to be his "final thumbs up" last month, his fundraising efforts stepped up a gear.
A campaign on social media with the hashtag "ThumbsUpForStephen" was born to help Stephen reach his fundraising target.
Soon the Teenage Cancer Trust had received more than £3 million in donations in his name.
Celebrities including Stephen Fry, Benedict Cumberbatch and Russell Brand have backed Stephen's fundraising efforts, which has included a fundraising comedy gig set up by support Jason Manford.
He was even visited by the Prime Minister while in his hospital bed.
Mr Cameron, who gave Stephen a letter saying he was humbled by his bravery and positive attitude, said after their meeting: "He's amazing, just an inspiration.
"Here's this guy who is fighting a disease but he's also got time to inspire hundreds of thousands of people."
Anticipating how others would view him after his death, Stephen once told his supporters on YouTube: "For whatever reason, life has given me cancer.
"I don't want to be remembered as someone who didn't fulfil their potential.
"My original goal was to become a doctor and to help others that way. Unfortunately my diagnosis means that I won't be able to fulfil that dream - however, my core purpose of helping others is still the same."
Watch Stephen tell ITV News Central how he was determined to leave the world with a smile on his face and he "didn't want anyone to feel sorry for him".