Slayer’s Jeff Hanneman died of liver failure in a California hospital on Thursday; he was 49. The guitarist co-founded the pioneering metal group in 1981, penning the lyrics to many songs along the way. Hanneman was beset with a rare flesh-eating disease called necrotizing fasciitis in 2011, though he was said to have recovered. The band has continued touring and recording records since its inception, releasing World Painted Blood, its tenth studio album, in 2009.