Commercial Appeal reports that Koopsta Knicca, a founding member of the great Memphis rap crew Three 6 Mafia, has died at a Memphis hospital. Koopsta suffered from a stroke on Sunday, and he had been on life support ever since. He was 40.

Koopsta, born Robert Cooper Phillips, helped found Three 6 Mafia in 1991; he’d gone to the same high school as fellow Mafia members DJ Paul and Juicy J. On Three 6 classics like “Who Run It” or “Tear Da Club Up ’97,” Koopsta would rap last, his eerie wheezing singsong leaving an indelible impression.

He stayed with the group through its precipitous rise in the late ’90s, and he released the solo album Da Devil’s Playground in 1999. In 2000, when the group’s popularity was exploding, he left because a prison sentence made it impossible for him to tour or record. He continued to crank out solo underground albums and rejoined most of the group’s original members in the new group Da Mafia 6ix in 2013.

In a statement to Commercial Appeal, DJ Paul says, “Everyone who knew Koop knew he was very funny and the coolest guy ever. He will be missed. We made classics together that’ll live on.” He also says that he and Koopsta had begun to write the new album Devil’s Playground 2 but that they hadn’t started recording it yet.

Koopsta is the second original Three 6 Mafia member to die suddenly and unexpectedly in recent years. Fellow Triple 6 rapper Lord Infamous passed away in December 2013.

Below, watch Koopsta and his Triple 6 crew in a couple of videos.