Five years ago, Duangphet Promthep survived a harrowing test of human endurance under rock and in darkness — the 13-year-old captain of a Thai soccer team that had been trapped before being rescued from a flooded cave in an effort that became a global drama.
He moved to England last year after securing a scholarship to a soccer academy that promoted its high-level program and international student population. “I promise I will focus and do my best,” he wrote on social media at the time, later posting photographs of his classes and the school grounds.
Dom, as he was known to his friends, eluded one tragedy, but not a second. He died on Tuesday, according to his family and the Zico Foundation, a Thai nonprofit group that helped him win the scholarship. He was 17.
No cause of death was given, but Kiatisuk Senamuang, the Zico Foundation’s founder, told reporters on Wednesday that a teacher found the student unconscious in his dorm room on Sunday afternoon. He died in a hospital after becoming unresponsive.
“We are waiting for his body to return,” his mother, Thanaporn Duangthep, said at a virtual news conference from the town of Mae Sai, in northern Thailand. Her son, she said, had at least fulfilled his dream of being a soccer student abroad.
The teenager found himself in the international spotlight five years ago as one of 12 boys who ventured into Tham Luang Cave in Chiang Rai Province along with their coach after soccer practice.
Heavy rain filled the cave entrance, pushing the group deeper into a warren of complex underground passages to avoid drowning and leaving them trapped.
The team’s path to survival became a closely watched global drama, and their extraordinary escape was hailed as a miraculous feat of human collaboration. Found alive more than a week after they went missing, the group had survived by conserving energy and licking water off the cave walls.
Their eventual rescue, more than a week later, ultimately involved Thai Navy Seals, expert cave divers from around the world and workers from several government agencies, and the use of pumps to keep water levels at bay.
Divers used guide ropes and air tanks placed along the dangerous two-mile route and held the boys, who wore full face masks, under their bodies as they navigated each crevice — a four-hour ordeal. The team survived, but one volunteer diver, Saman Gunan, died when he lost consciousness after a journey to place air tanks along the route.
In the dark underground, Dom had celebrated his 13th birthday, said Vernon Unsworth, one of the cave rescuers.
When the avid soccer player said in August that he had won a scholarship to attend the Brooke House College Football Academy in Leicestershire in England, about 75 miles northwest of London, he referred to it on Instagram as “an important moment” in his life.
“Today my dream has come true,” he said. The soccer academy has billed itself as a training ground that has sent multiple players on to professional careers.
The school said in a statement on Wednesday that it was devastated by his death. “We unite in grief with all of Dom’s family, friends, former teammates and those involved in all parts of his life,” they said. The school added that it was in contact with the Thai Embassy in London but declined to release more details.
A spokesman for the Leicestershire Police said that officers had been called to the school on Sunday afternoon, and that a 17-year-old student had died after being taken to a hospital. The death, they said in a statement, was not being treated as suspicious.
Dom’s former teammates shared their condolences online on Wednesday, mourning a promising future cut short and pointing to the hardships they had survived together.
Describing their friend as a brother who motivated them to pursue their ambitions in the sport, they said he aspired to play for Thailand’s national team.
“When we met last time before you left for England, I still jokingly said to you that I have to get your autograph when you come back,” said Prachak Sutham, who was a member of the team, known as the Wild Boars, that was rescued from the cave. “Rest in peace my friend, there will always be 13 of us.”
“You are one of the persons who pushes me and makes me want to develop myself to your level,” said another teammate, Chanin Viboonrungruang. “If next life is real, I wish we will play football together as a team again.”
He had been happy in England, said Mr. Kiatisuk, and wanted to continue playing soccer.
“The sad thing is he was given the opportunity he wanted in life and now his life is suddenly been taken away at a very young age,” said Mr. Unsworth, one of the rescuers, adding that there were not enough words to describe the outpouring of grief. “Life is very cruel.”