Hancock County Coroner Kendall Beals said an autopsy shows the father of Sheriff Scott Bentzinger died of a heart attack.
Michael Bentzinger, 63, passed away at his business, Bentzinger Home Supply Store, in downtown Carthage Monday night.
Beals said Bentzinger died before a fire started that destroyed the building. He said the fire appears to have been caused by an LP heater.
The Hancock County Sheriff's Office said emergency responders were dispatched to the scene at 10:27 p.m. The building sustained major fire and water damage.
The Illinois State Fire Marshal Investigator and the Illinois State Police CSI are involved in the investigation of the fire.
Fire departments from Hamilton and Keokuk assisted the Carthage Fire Department.
