ADA TOWNSHIP, Mich. (AP) — A 61-year-old California man who died while competing in a western Michigan triathlon had an enlarged heart and signs of a previous heart attack.

That is the conclusion from Dr. Stephen Cohle (COAL), the medical examiner in Kent County, Michigan, after an autopsy.

Gary Grunwald of Elk Grove, California, died Sunday during the run portion of the USAT Clydesdale & Athena National Championship near Grand Rapids.

The sheriff's office says event staff immediately started resuscitation efforts. Grunwald was pronounced dead at a hospital.