ELK GROVE (CBS13) – An Elk Grove man died while running a triathlon in Michigan over the weekend.

Gary Grunwald, 61, was running in the USAT Clydesdale and Athena National Championship in Ada Township, Michigan on Sunday.

He was three miles from the finish line when he collapsed and died.

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Officials say the cause of death is unclear.

Grunwald worked as a contractor for the City of Elk Grove.

His family says he was a great father, brother, husband, friend and was doing exactly what he loved when he died.