A man who strangled his girlfriend died of a heart attack while burying her body in the backyard, investigators say.
Joseph McKinnon's body was found on Saturday in the small town of Trenton, South Carolina, after neighbours reported an unconscious man.
Emergency services were called out but could not revive him.
As sheriff's deputies investigated the 60-year-old's death, they found a body wrapped in bin bags in a newly dug hole.
It turned out to be his partner, Patricia Dent, 65, said a statement from Edgefield County Sheriff's Office.
A post-mortem found that she had been strangled and neighbours recalled seeing McKinnon digging a hole in the yard the day before.
McKinnon died of a heart attack, according to an examination of his body.
Authorities said it appeared he'd nearly finished filling in the grave when he put down his spade, walked away and collapsed.
Both of the deceased lived at the same home on Tanglewood Drive, according to authorities.
Ms Dent's twin sister, Pamela Briggs, told Fox Carolina: "I would say a nightmare, and I want to wake up, and it's a dream. I know it's not.
"This is reality and life, and a big part of me is gone, and now I'm going to have to live with that."