Well-known American football journalist Grant Wahl died on Friday after suffering "acute distress" while covering a match at the World Cup in Qatar, his agent said.
U.S. Soccer said it was "heartbroken to learn" of Wahl's death. His wife responded to the U.S. Soccer statement on Twitter, saying she was "in complete shock".
Wahl, a former Sports Illustrated sportswriter who moved to the Substack online publishing platform, had been tweeting about the Netherlands-Argentina match earlier on Friday.
His agent, Tim Scanlan, told Reuters that Wahl had "appeared to suffer some kind of acute distress in the start of extra time" at the quarter-final match.
Scanlan said attempts were made to revive Wahl in the press box before he was taken by stretcher to a local hospital, where he was confirmed dead.
FIFA, football's world governing body, did not immediately respond to a request for comment.
Qatar’s international media office and World Cup organiser, the Supreme Committee for Delivery and legacy, did not immediately respond to Reuters request for comment.
"Everyone's emotional and it's really traumatic," Scanlan said. "He was a true advocate for both the men's and women's games and really just cared deeply about the sport. He was empathetic and just truly a brilliant writer."
Wahl said in late November he was briefly detained when he tried to enter a World Cup stadium in Qatar while wearing a rainbow shirt.
He wrote on Monday that he had visited a hospital while in Qatar.
"I didn't have Covid (I test regularly here), but I went into the medical clinic at the main media center today, and they said I probably have bronchitis," he posted on Substack.
US State Department spokesman Ned Price said on Twitter the department had been in close communication with Wahl's family.
"We are engaged with senior Qatari officials to see to it that his family’s wishes are fulfilled as expeditiously as possible," said Price.
The U.S. soccer community shared in an immediate outpouring of grief over the news.
"He was a kind and caring person whose passion for soccer and dedication to journalism were immeasurable," Major League Soccer Commissioner Don Garber said in reaction to news of Wahl's death.
"This is so devastating," twice World Cup winner Megan Rapinoe said on Twitter. "All the love to his family and loved ones."