MEMPHIS, Tenn. (WTVO) — Lola Mitchell, aka Three 6 Mafia member Gangsta Boo, was found dead Sunday. She was 43.

Although no cause of death was announced, TMZ cited sources close to the rapper who claim her death was due to an apparent overdose.

TMZ also reported that Boo was attending a concert in Memphis with her brother, who overdosed and required hospitalization. He later recovered.

A fentanyl-laced substance is suspected to be responsible for her death.

Boo was one of rap’s pioneering female artists and gained fame as part of Three 6 Mafia, alongside DJ Paul, Juicy J, Lord Infamous, Crunchy Black, Koopsta Knicca, and more.

The group earned an Oscar for Best Original Song for their song “It’s Hard Out Here for a Pimp” from the film Hustle & Flow.