A South Carolina man died of a heart problem while burying the woman he strangled, deputies say

(CNN) — A 60-year-old man strangled a woman and tried to bury her in the backyard of his South Carolina home, but had a “cardiac event” in the process of plugging a hole and died, according to a statement. Edgefield County Sheriff’s Office press release. Officers responded to the Trenton home Saturday morning for calls from a man lying unconscious in his yard. They identified him as Joseph McKinnon, who had no signs of trauma “and natural causes were suspected,” according to the statement. When officers notified relatives, a second body was found in the newly dug hole, according to the release. Authorities identified those remains as 65-year-old Patricia Dent, who also lived in the home. Dent “apparently died of criminal action,” the statement said. An investigation led officers to believe that McKinnon attacked Dent inside her home, according to the statement. Agents said McKinnon then tied her up and wrapped her in garbage bags before putting her in the previously dug hole in the yard. While covering the hole, McKinnon had a cardiac event that caused his death, according to the release. The Edgefield County Coroner’s Office ruled McKinnon’s cause of death was natural causes. Dent’s death was due to strangulation. Trenton is about 25 miles northeast of Augusta, Georgia. CNN’s Katherine Dillinger contributed to this report.