This weekend has been full of unpleasant events. First Bernie Mac died, now Academy Award winner Isaac Hayes passed away Sunday afternoon, Shelby County Sheriff's Office said.

The 65-year-old singer, songwriter whose theme for the 1971 action film "Shaft" won him an Oscar and a Grammy award, was found by a family member laying unconscious next to a running treadmill in his basement around 1 p.m. local time, said Steve Shular, a spokesman for the Shelby County Sheriff's Office in a telephone interview.

"The family had last seen him about noon," Shular told People.com."Family members had gone to the grocery store and left him home. When the family came home around 1, his wife's cousin found him lying on the floor in the basement near a treadmill. The treadmill was running, so it is believed that he had been working out."

Hayes was pronounced dead at Baptist East Hospital where doctors are still trying to determine the cause of death but no autopsy is planned, Shular added.

According to his family, the Rock and Roll Hall of Fame inductee had a history of high blood pressure and was recently treated for various medical conditions.

Hayes was one of the most influential soul artists. His second album, 1967’s "Hot Buttered Soul" went multi platinum. He earned three Grammy Awards during his career and an Oscar for best original song for the Theme from "Shaft."

From the late 1990s to 2006, Hayes played the oversexed smooth-talking animated character Chef on "South Park." Hayes was a Scientologist and cited religious intolerance on South Park’s “Out of the Closet” Tom Cruise parody as his reason for leaving the show in 2006.

He is survived by 12 children, 14 grandchildren and three great-grandchildren. His youngest child is a two year old son, Nana Kwadjo Hayes, with his fourth wife, Adjowa.