Tyler Duckworth, a two-time winner of “The Challenge,” has died at the age of 44.

His mother, Joni Duckworth, confirmed his death on Facebook Thursday, saying that a cause of death has yet to be determined, but that the reality star had passed earlier in the week.

“My son, Tyler, passed away earlier this week,” his mother wrote on Facebook. “Cause of death has yet to be determined. I will post on Facebook about services as soon as his dad and I figure it out.”

Duckworth last posted on Instagram to commemorate his surprise appearance at “The Challenge Mania” fan event in his hometown of Minneapolis, Minn. He posed alongside fellow alums Rachel Robinson, Brad Fiorenza, Tina Barta and Mark Long in the Aug. 2 post.

“So proud to represent my hometown of Minneapolis along with these other challenge legends,” he wrote. “The fans are what keep us coming out! Hearing your stories of courage, inspiration & joy that you’ve got being a fan of the franchise is humbling each and every time.”

Duckworth appeared on six seasons of “The Challenge,” including “The Duel,” “The Gauntlet III,” “Cutthroat,” “Rivals,” “All Stars 2” and “All Stars 3.” He was crowned champion two times in a row on “Cutthroat” and “Rivals.”

His most recent appearance with the franchise was on “All Stars 3” in 2022, and he said he worked as a middle and high school teacher at the time.

“This sounds really sappy, but when you’ve already won, especially two in a row, for me it was more about: I just want to compete,” Duckworth told Entertainment Weekly ahead of the season. “I want to see if I still have it, if I can jump off crazy-high things or if I can do puzzles.”

He began his reality TV career on MTV’s “The Real World: Key West” in 2006.

Bunim/Murray Productions, the company which produces “The Challenge” and “The Real World,” remembered Duckworth as “an exceptional human being,” following the news of his death.

“Tyler was truly part of the Bunim/Murray family, he was an exceptional human being and beloved by both fans and his fellow contestants alike on ‘The Challenge,’” a spokesperson for the production company shared in a statement to TheWrap. “He will be missed by us all and our heart goes out to his family, his friends and everyone who enjoyed watching him compete on the show across so many seasons.”

One of Duckworth’s cast members, who recently reunited with him at the “Challenge Mania” fan event, Barta reflected on their friendship following the news of his death.

“It’s hard to find the right words when someone who was part of such a meaningful chapter of your life is suddenly gone,” she captioned an instagram video of the two of them. “We shared an experience that very few people will ever fully understand, and somewhere along the way, it became more than a show or an adventure. It became friendship. It became history. It became family.”

“How blessed am I to be surprised by your visit to Challengemania where I got to hug and kiss you one last time,” she added. “We didn’t want to leave each other. We never do. I love you.”