Duangpetch Promthep, one of the 12 boys who was rescued from a Thai cave in 2018, has died in the UK.
The cause of the death is unclear, but the 17-year-old is reported to have sustained a head injury.
He enrolled in the Brooke House College Football Academy in Leicestershire late last year.
He was the captain of the Thai boys' football team, which was trapped along with their coach for over two weeks while exploring in Chiang Rai province.
His emaciated but grinning face caught in the light of a diver after the boys were found in the cave was one of the most memorable images from the remarkable rescue.
In August last year, his team mates rejoiced when Promthep, who they call Dom, announced on Instagram that he had won a scholarship to join a football academy in Britain - "today my dream has come true," he wrote.
Just six months on, they are mourning the loss of their friend.
News of his death emerged after his mother informed the Wat Doi Wao temple in his home town in Chiang Rai, which the team frequented. "May Dom's soul rest in peace," said the post, which was accompanied by pictures of the football team with monks.
Soon, messages began pouring in from his team mates.
"You told me to wait and see you play for the national team, I always believe that you would do it," wrote Prachak Sutham, one of the boys who was rescued with Promthep in 2018.
"When we met the last time before you left for England, I even jokingly told you that when you come back, I would have to ask for your autograph. Sleep well, my dear friend. We will always have 13 of us together."
Another of the boys, Titan Chanin Viboonrungruang, wrote: "Brother, you told me that we would be achieving our football dream. You are one of the persons that pushes me and makes me wanting to improve myself to your level. If the next world is real, I want us to play football together again, my brother Dom."