Elite swimmer To died while training for the 2020 Tokyo Olympics, the Hong Kong Sports Institute said in a statement.
To fell ill during a training session in Florida on March 18, according to the Associated Press. He was taken to the hospital, where he later died, the Hong Kong Sports Institute said. He was 26.
The cause of To's death was not immediately clear.
Born in Hong Kong, To moved to Australia as a child. He won six medals at the 2010 Youth Olympics in Singapore, taking the gold medal in the 400-meter medley. He later won a silver medal as part of part of Australia's 400-medley relay squad at the 2013 world championships in Barcelona.