May 2, 2013— -- Chris Kelly, one half of the '90s rap duo Kris Kross, has died of a possible drug overdose, Georgia authorities said.
Kelly, 34, was pronounced dead Wednesday night at the Atlanta Medical Center, Clint Harbin, an investigator with the Fulton County Medical Examiner's Office, told ABC News Radio.
Authorities are investigating the circumstances surrounding his death and an autopsy is expected to be performed later today.
"It appears it may have been a possible drug overdose," said Cpl. Kay Lester, a spokeswoman for the Fulton County police, according to The Associated Press.
Kelly (known as "Mac Daddy"), along with Chris "Daddy Mac" Smith, the backward-pants-wearing mini-rappers, rose to fame with their song "Jump" from their 1992 album, "Totally Krossed Out."
"Jump" hit No. 1 on the Billboard Hot 100 chart and remained there for eight weeks.
Kelly and Smith were discovered by music producer and rapper Jermaine Dupri in an Atlanta mall. Kelly was 13 when "Totally Krossed Out" was released. The album went on to multiplatinum status thanks to "Jump," which remained a popular song throughout 1992.
They toured with Michael Jackson later that year during his "Dangerous World Tour."
Their gimmick of wearing clothes backward won over legions of fans and allowed the duo to cross over into mainstream success. They even went on to release their own video game titled "Kris Kross: Make My Video" for the Sega CD console.
They released "Da Bomb" in 1993, which failed to match the success of their prior album. One of the singles off the album, also titled "Da Bomb," featured female rapper Da Brat.
The group's last album, "Young, Rich & Dangerous," was released in 1996 and reached gold status.
Earlier this year, the group performed together in Atlanta to celebrate the 20th anniversary of Dupri's label, So So Def.
"He actually was still working on music and recording," said Yahoo music writer Billy Johnson Jr., who interviewed Kelly in February.
"He said he had several hundred songs that he had recorded and he had mentioned that during his time away from releasing music that he had actually gone back to school to learn how to be a studio engineer," Johnson said, according to ABC News Radio.
Johnson also discussed questions about Kelly's health after pictures surfaced online with patches of his hair missing.
"I asked him about that and he said he had skin disease called alopecia and he said that those rumors had been very hurtful because people thought he had cancer and it wasn't true," Johnson said.
Rapper LL Cool J tweeted a link to his new song, "Jump on It," and dedicated it to Kelly.
"R.I.P Chris Kelly. This song is now officially dedicated to you. May GOD embrace your soul & lift up your family," he tweeted."
Hip-hop mogul Russell Simmons and Da Brat also both tweeted condolences overnight.
ABC News' Jason Nathanson and The Associated Press contributed to this report.