Dave Mustaine, frontman of Megadeth, tweeted: "Tonight one less star will be shining and sadly, the stage got just a little bit darker. Jeff Hanneman 1964-2013."
Hanneman has been off the road since early 2011, when he contracted necrotizing fasciitis -- most likely from a spider bite -- a quick-progressing disease that literally eats away at the flesh from deep layers of skin and tissue. Exodus' Gary Holt stood in for Hanneman starting in February of 2011, while Pat O'Brien joined the band when Holt returned to Exodus during 2011.
It's not known what role the disease played in Hanneman's liver failure.
Throughout the ordeal, Hanneman's bandmates expressed optimism that he would one day return to the group full-time. Bassist-singer Tom Araya told Billboard during last year's Rockstar Energy Drink Mayhem Festival tour that Hanneman was "free of the disease" and was "working on his playing ability...He's working on strengthening his arm and his ability to play." He predicted that Slayer would "probably get together and start writing together and start making a new album," the group's first since 2009's "World Painted Blood," with Hanneman contributing material.
But in February guitarist Kerry King told Australian press that "we don't know when Jeff's gonna be able to play guitar. Jeff's kind of like a wait-and-see thing."
Born in Oakland, Calif., and a devoted Raiders fan, Hanneman was raised primarily in Long Beach and became fascinated with wars and military campaigns -- themes he'd bring to Slayer's music -- via his father, a World War II veteran, and brothers who served in Vietnam. He met King in 1981 and decided to form their own band, mixing heavy metal and punk influences and signing with Metal Blade Records for Slayer's first two albums, "Show No Mercy" in 1983 and "Hell Awaits" in 1985. The group made an eyebrow-raising move to the hip-hop label Def Jam in 1986 for the covers album "Undisputed Attitude and the classic "Reign in Blood."
A spokesperson for "Blood" producer Rick Rubin told Billboard he was "very sad" and "shocked" by the news of Hanneman's death.
Slayer has released ten studio albums and two live albums, as well as a pair of EPs. They've sold 4.9 million albums in the SoundScan era (1991-present), with the classics "Reign in Blood" (1986), "South of Heaven" (1988) and "Seasons of the Abyss" (1990) accounting for over 2 million of that tally. Ten of their albums have charted on the Billboard 200, with 2006's "Christ Illusion" being the highest debut at No. 5.
Hanneman had a hand in crafting most of the group's best-known thrash anthems. Begin typing "Slayer" on YouTube and the songs "Raining Blood," "Angel of Death," "Seasons in the Abyss" and "South of Heaven" appear first -- all of them written or co-penned by Hanneman. "Raining Blood," a blistering track off "Reign in Blood," stands as the band's biggest selling song with 205,000 sold to date.
Hanneman, an ardent collector of World War II memorabilia, was at the center of the controversy over Slayer's supposed Nazi sympathies, stemming from the resemblance of the group's eagle logo to a Third Reich image and the shape of the S in the group's typography, and from songs such as "Reign in Blood's" "Angel of Death," about German doctor Josef Mengele and his horrific "experiments" at the Auschwitz death camp. But Hanneman frequently explained that the song was in no way intended to glorify Mengele. "I know why people misrepresent it," he told one radio interviewer. "It's because they get a knee-jerk reaction to it. There's nothing I put in the lyrics that says necessarily he was a bad man because to me -- well, isn't it obvious? I shouldn't have to tell you that."
Hanneman's songs have been recorded by groups such as Hatebreed, Children of Bodom, Hellsongs, Cradle of Filth and others, and sampled by rapper Styles-P. He's survived by Kathy, his wife of 16 years, sister Kathy and two brothers, Michael and Larry. Funeral arrangements are pending.