Photo: Denise Truscello/WireImage

LAS VEGAS, NV - NOVEMBER 30: Stephan Bonnar arrives at the 2011 Fighters Only World Mixed Martial Arts Awards on November 30, 2011 in Las Vegas, Nevada. (Photo by Denise Truscello/WireImage)

Stephan Bonnar, a professional wrestler and Ultimate Fighting Championship (UFC) Hall of Famer, has died. He was 45.

Bonnar died from “presumed heart complications while at work,” the UFC said in a news release on Saturday.

“Stephan Bonnar was one of the most important fighters to ever compete in the Octagon,” UFC President Dana White said in a statement.

“His fight with Forrest Griffin changed the sport forever, and he will never be forgotten,” he added. “The fans loved him, related to him and he always gave them his best. He will be missed.”

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David Becker/WireImage

LAS VEGAS, NV - MARCH 02: Mixed martial artist Stephan Bonnar presents the MMA Media Source of the Year award during the ninth annual Fighters Only World Mixed Martial Arts Awards at The Venetian Las Vegas on March 2, 2017 in Las Vegas, Nevada. (Photo by David Becker/WireImage)

Bonnar first made a name for himself on season one ofThe Ultimate Fighterin 2005, when he was pit against Forrest Griffin during the show’s finale.

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In the years to follow, Bonnar would go on to defeat other athletes among the likes of James Irvin, Keith Jardine, Krzysztof Soszynski, Igor Pokrajac and Kyle Kingsbury, per the UFC.

Before ending his career with a 17-9 record, he also faced fellow Hall of Famers Jon Jones, Rashad Evans, Mark Coleman, Anderson Silva and Tito Ortiz, the organization added.

Felipe Dana/AP/Shutterstock

Mandatory Credit: Photo by Felipe Dana/AP/Shutterstock (6857009a) Stephan Bonnar Mixed martial arts fighter Stephan Bonnar, from the U.S., poses during the UFC 153 weigh-in event in Rio de Janeiro, Brazil, . The Ultimate Fighting Championship organization is holding fighting events on Saturday Brazil UFC, Rio de Janeiro, Brazil

After news of his death was made public, various stars paid tribute to Bonnar on social media.

“Stephan Bonner a key piece to the growth of our sport,” retired UFC star Frankie Edgartweeted. “I remember watching him and Forest battling it out and thinking, I gotta try this out. RIP to a true pioneer!”

“RIP to the American Pyscho, Stephan Bonnar. I remember watching him and Anderson Silva,” Jake Paulsaid.

“We lost a real legend,” UFC commentatorJoe Roganwrote in anInstagram post, adding that Bonnar will “not be forgotten.”

source: people.com