Retired pro cyclist Stephen Wooldridge, who won a gold medal for Australia in the team pursuit event at the 2004 Athens Olympics, died Monday at age 39.

The cause of death has not been released by authorities, but close friend and cycling mentor Phillip Bates said Wooldridge died of an apparent suicide.

“Tragically today he gave his life away leaving behind a son and daughter, family and friends just short of his 40th birthday,” Bates wrote on Australian cycling website Ride Media.

Wooldridge, who was inducted into the New South Wales Sports Hall of Fame in 2015, will be remembered for his vast contributions to the cycling world. Not only did he help Team Australia win gold at the 2004 Olympics, he also picked up five medals at the world championships between 2002 and 2006, all gold except for 2005 when he won the bronze with Team Australia.

After his pro career ended, he remained in the sport, taking on promotional and fundraising roles.

“Stephen was an exceptional cyclist and Olympic Champion who will forever be remembered,” John Coates, the Australian Olympic Committee president, said in a statement (via the Sydney Morning Herald). “He was always very giving of his time to the Olympic movement, helping out with fundraising efforts whenever he could for the Australian Olympic Team over the years.  … Our deepest condolences are with his family, friends and all of those impacted by Stephen’s passing.”

Fellow Australian cyclist Bruce-John McIntosh also expressed his shock upon hearing the news. He penned a long essay to Wooldridge on Facebook late Monday night.

“I am lost for words,” McIntosh wrote. “You have left thousands of broken hearts with family and friends that will never recover, but this is about you. How did it come to this? You had a loving family, amazing friends, achieved more than most people could ever achieve in 10 lifetimes.”

McIntosh added, however, that Wooldridge’s mental health issues, while tragic, may not be that rare.

“I can think of hundreds of professional athletes that battle the same struggles,” McIntosh wrote. “There is not a person in my life that at some stage [hasn’t] battled with something, we should not pigeonhole our high profile athletes that they also don’t struggle with their own battles.”

He added: “There must be a better way, I / we /us must make this a line in the sand to start to make a difference.”

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