Medical examiners have determined that a man whose badly burned body was found Monday in an irrigation ditch died of a heart attack and not of smoke inhalation.

The body of Earl F. Simpson, 66, was found in a ditch about a quarter of a mile from his house. His body was face up near a shovel and a burned board.Weber County Sheriff's officer Archie Smith told the Deseret News Tuesday that the medical examiner discovered "obvious signs of coronary disease" during the autopsy. The carbon dioxide level was very low, indicating no smoke inhalation.

"He died prior to being burned," Smith said.

Simpson had gone to the field earlier that day to burn an irrigation ditch and did not return.

His brother, Eldin E. Simpson, 64, went out to the field to look for his brother. When he first saw the body from a distance, he mistook it for a burning log. He then recognized it was his brother.