Avenged Sevenfold drummer Jimmy “The Rev” Sullivan was found dead at his home in Huntington Beach, California, yesterday. He was 28. Preliminary police reports indicate Sullivan died of natural causes, but the Orange County Coroner’s Office is investigating his death, the OC Register reports. Sullivan helped found Avenged Sevenfold in 1999, and featured on all four of the band’s studio albums.

“It is with great sadness and heavy hearts that we tell you of the passing today of Jimmy ‘The Rev’ Sullivan,” Sullivan’s Avenged Sevenfold bandmates wrote on their Website. “Jimmy was not only one of the world’s best drummers, but more importantly he was our best friend and brother. Our thoughts and prayers go out to Jimmy’s family and we hope that you will respect their privacy during this difficult time. Jimmy you are forever in our hearts.”

After playing Ozzfest in 2006, Avenged Sevenfold memorably beat out Rihanna, Chris Brown, Panic! at the Disco, Angels and Airwaves and James Blunt for the title of Best New Artist at the MTV Video Music Awards, thanks in part to their Fear and Loathing in Las Vegas-inspired song “Bat Country.” Avenged Sevenfold then reached Number Four on the Billboard Top 200 with their self-titled fourth album. The band spent the past two years on a co-headlining tour with Buckcherry. The band was reportedly in the process of recording their fifth album.