Reality TV star Tyler Duckworth, who first appeared on MTV’s The Real World: Key West and went on to compete on six seasons of The Challenge, winning twice, has died. He was 44.

His mother, Joni, announced her son’s death Thursday on Facebook. “My son, Tyler, passed away earlier this week,” she wrote. “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.”

The Sun, which first reported his death, revealed Duckworth was found unresponsive in his bathroom on Tuesday. The publication cited officials in North Dakota as saying the death was classified as unattended, meaning there were no witnesses there at the time.

His death came nearly two weeks after he appeared at The Challenge Mania event on July 31 in Minneapolis. He posted a photo of himself alongside fellow Challenge alums on Instagram on August 2.

“@challengemaniapodcast always knows how to bring the BEST of the BEST together!!, he wrote. “So proud to represent my hometown of Minneapolis along with these other challenge legends. 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. Also, pretty sure we nailed the cast photo for the lost season of The Real World: Minneapolis!! Thank you Minneapolis!”

Born March 5, 1981, in Atlanta, GA, he grew up in Minneapolis. He appeared on The Real World: Key West in 2006 and went on to compete on six seasons of The Challenge – The Duel, The Gauntlet III, Cutthroat, Rivals, All Stars 2 and All Stars 3 — winning Cutthroat and Rivals. On Cutthroat, he won a bruising, 40-minute elimination round against heavy hitter CT Tamburello after Johnny “Bananas” Devenanzio was eliminated in what has been remember as the “Bananas Backpack” match. After 10 years, he returned to the franchise for All Stars 2.

After his run on reality TV. Duckworth became a middle school and high school teacher and was actively pursuing a doctorate degree, according to an interview with Entertainment Weekly.