Sean Reinert, the acclaimed former drummer for Death and Cynic, has passed away. He was 48-years-old.

No cause of death has yet been revealed. According to The PRP, Reinert “was found unresponsive in his California home last night, January 24th.”

Reinert and his Cynic bandmate, guitarist/vocalist Paul Masvidal, appeared on Death’s influential fourth album, Human (1991), which is largely credited as one of the earliest examples of technical death metal. Cynic then went on to release their debut album, Focus, in 1993, which is also considered another important early entry in the tech-death genre, further expanding the sound to include an array of other, non-metal influences.

Cynic disbanded in 1994 and reunited in 2006. In 2008, they released Traced in Air, which was immediately hailed as another masterpiece. The band’s third, and to date final, full-length studio album, Kindly Bent to Free Us, was released in 2014.

That same year, Reinert and Masvidal both spoke out about what it’s like to be gay in the metal scene. Judas Priest singer Rob Halford, another pioneer in the LGBTQ metal community, praised the move as “a fucking great thing to do.”

Reinert split with Cynic in 2015. That same year, he was forced to leave the Death to All tour — a rotating reunion of surviving Death members — due to “suffering from lower back spasms, extreme muscle fatigue and limited grip strength.”

In 2017, Reinert and Masvidal reached a settlement over the Cynic name.