U.S. sports journalist dies at World Cup, world reacts

(CNN) - The death of American journalist Grant Wahl is sending shock waves throughout the sports world, after he collapsed and died while covering the World Cup in Qatar.

The U.S. Soccer community, among others, are paying tribute while a cause of death remains unclear.

"He believed in advocacy. He was somebody who always wanted the game to be better, and he wanted to root out corruption," Sports Editor David Zirin spoke.

Not only that, Wahl's death comes as a major shock to the sports world.

Shouting for medical assistance

On Friday, he collapsed while covering the FIFA World Cup in Qatar.

A columnist closeby says paramedics treated Wahl for about 20-25 minutes in the stadium before they moved him to the hospital.

"Suddenly, colleagues up to my left started shouting for medical assistance," said Columnist Keir Radnedge.

"The medical team were there pretty quickly, and you know, we're able to as best they could give treatment."

Sports world reacts

Meanwhile, U.S. Soccer tweeted, "The soccer community is heartbroken by the news. We are devastated that he and his brilliant writing will no longer be with us."

Tennis great Billie Jean King then posted this message.

"A talented journalist. Grant was an advocate for the LGBTQ community and a prominent voice for women's soccer."

NBA star Lebron James also sending his condolences to the family of the man who wrote the iconic "Chosen One" story on James, then a high schooler, for Sports Illustrated in 2002.

"Any time his name would come up, I always think back to me as a teenager and having Grant, you know, in our building...it's a tragic loss."

Feeling unwell

In an episode of the podcast "Futbol with Grant Wahl," published December 6, he had complained of feeling unwell.

So far, medical professionals have not determined the cause of death.