Chris "Mac Daddy" Kelly, one-half of the rap group Kris Kross, passed away Wednesday afternoon (May 1) from unknown causes, reports the Atlanta Journal-Constitution. Kelly was 34 years old.

Kelly was found unresponsive in his home and was rushed to Atlanta Medical Center, where he was pronounced dead. The Medical Examiner's Office told the newspaper it could not provide more details about the circumstances of his death. An autopsy is planned for Thursday morning.

Kelly, along with Chris "Daddy Mac" Smith, were only 13 years old when legendary producer Jermaine Dupri discovered them at the Greenbriar Mall in 1990.

Together, the duo formed Kris Kross and achieved their first hit single in 1992 with 'Jump' from their multiplatinum debut album, 'Totally Krossed Out.' Among their other chart-topping songs were 'Warm It Up,' 'I Missed the Bus' and 'Da Bomb.'

Along with their infectious tunes, Kris Kross were also known for wearing their clothes backward, which became a fashion trend in the '90s.

Kris Kross reunited earlier this year at the 20th anniversary concert for Dupri's So So Def label.

"R.I.P Chris Kelly...May GOD embrace your soul & lift up your family," tweeted LL Cool J.

We send our heartfelt condolences to Chris Kelly's family. May he rest in peace. He will be sorely missed.

Watch Kris Kross' 'Jump' Video

Watch Kris Kross' 'Warm It Up' Video