Ironman Dean Mercer has died after his car crashed into a fence at Mermaid Waters on the Gold Coast.
The high-profile Gold Coast athlete was believed to be involved in the crash at around 7am Monday morning - it may have been caused by a medical incident A Queensland Ambulance Service spokeswoman told AAP.
Mercer, who won the Australian open ironman titles in 1989 and 1995 remained heavily involved in the sport. He began his career joining Nippers as a five-year-old in his home town of Thirroul, an hour's drive south of Sydney.
He was taken to hospital in a critical condition but had a cardiac arrest in the emergency room.