Jimmy "The Rev" Sullivan, the drummer for Avenged Sevenfold, died from an accidental overdose.

Cause of Death

Toxicology reports confirmed acute polydrug intoxication from Oxycodone, Oxymorphone, Diazepam/Nordiazepam, and ethanol (alcohol). An enlarged heart (cardiomegaly) was noted as a significant contributing factor. The Orange County Coroner's office ruled it accidental, with no suspicion of foul play.

Timeline

Sullivan was found unresponsive at his Huntington Beach, California home on December 28, 2009, and pronounced dead at age 28. Initial autopsy was inconclusive, but results released in June 2010 finalized the cause.

Band Impact

Avenged Sevenfold lost a core member and co-songwriter, leading to tributes and a lasting legacy in their music. Fans and the band continue honoring him, especially around anniversaries.

TL;DR: Accidental overdose of prescription drugs and alcohol, compounded by an enlarged heart, on December 28, 2009.

Information gathered from public forums or data available on the internet and portrayed here.