Longtime soccer journalist Grant Wahl, who was covering the World Cup for CBS Sports in Qatar, died on Thursday while reporting on the quarterfinal match between Argentina and the Netherlands.

A cause of death has not been released publicly.

According to the Associated Press, "U.S. media seated near him said Wahl fell back in his seat in the media tribune at Lusail Iconic Stadium during extra time, and reporters adjacent to him called for assistance. Emergency services workers responded very quickly, the reporters said, and the reporters later were told that Wahl had died."

Wahl wrote on Monday that he had been sick for about 10 days, attributing it to being overworked and not getting much sleep while covering the World Cup before his symptoms eventually got bad enough that he went to a medical clinic in Qatar.

"I went into the medical clinic at the main media center today, and they said I probably have bronchitis," he wrote. "They gave me a course of antibiotics and some heavy-duty cough syrup, and I'm already feeling a bit better just a few hours later. But still: No bueno."

He said he tested negative for COVID-19.