*Isaac Hayes, an Oscar- and Grammy-winning music icon who helped to usher in the disco era, died Sunday afternoon after he collapsed near a treadmill, authorities said. He was 65.

The entertainer was pronounced dead at Baptist East Hospital in Memphis an hour after his body was found by a family member, the Shelby County Sheriff's Office said. The cause of death was not immediately known.

Sheriff's office spokesman Steve Shular said authorities received a 911 call after Hayes' wife, young son and his wife's cousin returned home from the grocery store and found him collapsed in a downstairs bedroom. A sheriff's deputy administered CPR until paramedics arrived.

"The treadmill was running but he was unresponsive lying on the floor," Shular said.

Hayes was preparing to record a new album for Stax, the soul record label he helped build to legendary status. And he had recently finished work on a movie called "Soul Men" in which he played himself, starring Samuel Jackson and Bernie Mac, who died on Saturday.

"I am deeply saddened by the loss of Isaac Hayes, a true historic world music figure," said the Reverend Al Sharpton, in a statement to EUR, who was to dedicate his Sunday night radio program to the late artist. "Isaac Hayes was the first African-American to win an Oscar for a music score but never lost sight of his commitment to his community and the betterment of mankind. He was more than an artist he was a trailblazer, He was an innovator. He was a creative genius. I shall never forget how in the height of his career he still had time to work and lend his celebrity to those of us much younger and at that time who were totally unknown. Even in his later years he never hesitated to appear for a cause or endorse something that he felt was for the good of mankind. He will be sorely missed."

With his trademark shades, bald head and deep baritone, Isaac Hayes laid the groundwork for not just disco, but also what came to be known as urban contemporary. He co-wrote the Sam and Dave hits "Hold On I'm Coming" and "Soul Man." He reached his commercial peak in 1972 when he won an Academy Award for his No. 1 hit "Theme from 'Shaft."'

Younger audiences are more familiar with Hayes as the voice of Chef on Comedy Central's animated series "South Park." But he left the show a few years ago because he disagreed with its attacks on Scientology, the religious movement to which he belonged.

Hayes was born in 1942 in a tin shack in Covington, Tenn., about 40 miles north of Memphis. He was raised by his maternal grandparents after his mother died and his father left when he was 1 1/2. The family moved to Memphis when he was 6.

Hayes wanted to be a doctor, but those dreams ended and were replaced with musical aspirations after he won a ninth grade talent contest by singing Nat King Cole's "Looking Back."

He released his debut album, the poor-selling "Presenting Isaac Hayes," in 1968. He broke through the following year with "Hot Buttered Soul," which contained just four songs but sold over a million copies.

His work on director Gordon Parks' urban crime drama "Shaft," a project he had hoped to star in, was the first of many forays into movie soundtracks. He got in front of the camera for the 1974 cult classic "Truck Turner" and had kept busy with film work ever since, recently appearing in the hip-hop drama "Hustle & Flow."

Community activist Najee Ali says a candlelight vigil for Hayes, as well as Bernie Mac, will be held at 6 p.m. tonight in Los Angeles at 5th Street Dicks coffeehouse in Leimert Park (4305 Degnan Blvd.)

Meanwhile, in addition to Sharpton, some of Hayes' friends and professional associates have issued statements expressing condolences and shared their memories:

• Dionne Warwick, a former musical collaborator, released this statement to Access Hollywood: "I've lost one of my best buddies and it is not easy to reckon with," she wrote. "I know one can never put a question mark where GOD puts a period, so I will not question the Almighty's decision to call him home. We all know when that call comes we all will answer... Personally, my buddy will be missed for many reasons by me. He was 'family.' He will be a part of my musical life each time I sing the song 'Deja vu' as this was a birthday gift to me from him. His renditions of songs that I had recorded especially 'Walk On By,' in my opinion, 'the definitive version' will always be another memory each time I sing it, and the humorous side that he showed few (that I knew so well). My family and I send sincere heart felt condolences to his family for their enormous loss, and we will hold them in continuous prayer."

• African American Film Critics Association president Gil Robertson IV said: "The loss of Isaac Hayes less than 24-hours after Bernie Mac represents a major double blow to the entire entertainment industry, black Hollywood in particular. The art form and expressions created by Isaac Hayes in particular resonated not only in American pop culture but throughout American life. Both are talents that will be missed but always remembered."

• Neil Portnow, President/CEO, The Recording Academy: "Three-time GRAMMY® winner Isaac Hayes was a true renaissance man -- singer, songwriter, producer, session musician, actor, activist and more. After laying the groundwork for the Memphis soul sound through his work with Stax Records, his groundbreaking theme song and score for the movie 'Shaft' cemented his status as a musical icon. He was actively involved with our Memphis Chapter, sharing his creativity with established professionals and up-and-coming musicians alike. The world has lost a true creative genius and a passionate humanitarian, but his indelible legacy will remain ever present. Our deepest sympathies go out to his family, friends and all who were inspired by the man and his music."