Chris Kelly, half of the 1990s rap duo who performed one of the decade’s most memorable songs, “Jump,” died May 1 at an Atlanta hospital of an apparent drug overdose, authorities said. He was 34.

Mr. Kelly, known as “Mac Daddy,” and Chris Smith, known as “Daddy Mac,” made up Kris Kross. The rappers were known for wearing their clothes backward as they rhymed.

Mr. Kelly’s mother, Donna Kelly Pratte, told authorities her son became sick after taking cocaine and heroin the night before he died. She said he had a history of drug abuse and had experienced similar episodes in the past.

Paramedics found Mr. Kelly unresponsive on a couch at his Atlanta home and administered CPR. He was later pronounced dead at a local hospital.

Betty Honey of the Fulton County Medical Examiner’s office said a toxicology screening is being done to determine cause of death.

In this 1992 photo, Chris Kelly, 13, belts out the hit tune “Jump” with help from fellow bandmate Cris Smith, behind, as their band Kris Kross performs on the Paramount stage at New York’s Madison Square Garden on Saturday, Sept. 5, 1992. (Joe Tabacca/AP)

Kris Kross was introduced to the music world in 1992 by music producer and rapper Jermaine Dupri after he discovered the pair at a mall in Atlanta.

The duo wore their clothes backwards as a gimmick, but they won over fans with their raps.

Their first, and by far most successful, song was “Jump.” The hit, from their multi-platinum 1992 debut album “Totally Krossed Out,” featured the two trading verses and rapping the refrain, which featured the song’s title.

The duo had surprising maturity in their rap delivery, though the song was written by a team that included Dupri. It would become a No. 1 hit in the United States and globally, and one of the most popular tunes of the year.

Their success led to instant fame: Kriss Kross toured with Michael Jackson, appeared on TV shows and had their own video game.

The group was never able to match the success of its first song, though it had other hits like “Warm It Up” and “Tonite’s tha Night.”

In 2009, after photos surfaced that showed Mr. Kelly with bald spots on his head, there were rumors that he had cancer. But in an interview posted on YouTube by Straight from the A TV, a gossip site, he said he suffered from alopecia, a condition in which people lose their hair.

“My health is good; I just got alopecia. I don’t have cancer, not other sort of diseases,” he said.

Earlier this year, Kris Kross performed to celebrate the anniversary of Dupri's recording label, So So Def.

Complete information about survivors could not be confirmed.

— Associated Press