Jeff Hanneman, guitarist, songwriter and founding member of thrash metal titans Slayer, died May 2 after suffering liver failure in a Southern California hospital. He was 49.

Though he had been forced to sit out several of his band’s live dates due to an illness contracted from a 2011 spider bite, the news of his death came as a surprise, as his bandmate Tom Araya had reaffirmed his place in the group as recently as last month. The band announced Hanneman’s death on its Facebook page, saying: “Slayer is devastated to inform that their bandmate and brother, Jeff Hanneman, passed away at about 11 a.m. this morning near his Southern California home.”

As one of the “Big Four” defining thrash metal bands of the 1980s – alongside Metallica, Megadeth and Anthrax – Slayer attracted an enormous cult audience with its string of blistering, Rick Rubin-produced records in the late 1980s and ’90s. Always the hardest-edged of the four, and an incalculable influence on metal’s more extreme subgenres, the band’s reputation only increased as many of its peers gradually pursued mainstream appeal, bequeathing Slayer a particularly devoted core of supporters and a “last band standing” image.

The band split songwriting duties among Hanneman, bassist-vocalist Araya and fellow guitarist Kerry King, though Hanneman was responsible for “Raining Blood” and “Angel of Death,” arguably the group’s best-known songs. Hanneman and King’s complementary solo styles made them one of metal’s premier lead guitar foils, though Hanneman’s love of punk rock and more structured approach to soloing always distinguished his playing.

Born in Oakland, Hanneman was raised in Long Beach, Calif., and began playing in metal bands after he met King when the two were teenagers. Forming Slayer alongside Araya with Dave Lombardo on drums, the group signed to Metal Blade Records early in the decade, turning heads with its punky first single, “Aggressive Perfector.”

Slayer released debut LP “Show No Mercy” in 1983, followed by EP “Haunting the Chapel.” These low-budget affairs showed the band still experimenting with its sound, which incorporated heavy notes from British black metal forebears Venom, yet they were effective in helping the band tap into the growing thrash metal underground. Second full-length “Hell Awaits” was a more progressive, atmospheric affair, and the band toured heavily in North America and Europe in support.

Slayer experienced an unexpected boost in its profile when Rubin – whose nascent Def Jam dealt almost exclusively in hip-hop – approached the band to sign for his label. With Rubin at the mixing boards, the band cleaned up and stripped down its style, and 1986’s “Reign in Blood” had an immediate, explosive impact within heavy metal circles. Clocking in at under half an hour (short enough to fit on a single side of a cassette), the album boasted blasts of jagged, almost surrealist song structures and demonic riffs delivered at blazing tempos previously unheard even in the speed-freak world of thrash. Featuring music and lyrics by Hanneman, lead-off track “Angel of Death” detailed the grotesque experiments of Nazi doctor Josef Mengele, and the mood hardly brightened from there.

With no radio airplay or real promotion – the record was quietly distributed by Geffen after Columbia Records refused to do so –  “Reign in Blood” was the first Slayer album to breach the top 100 of the Billboard album chart. It has since become regarded as a landmark of the genre, setting the stage for the even more outré death metal and grindcore styles to come.  Hanneman often cited the album as his personal favorite.

1988’s more low-key “South of Heaven” reached No. 57 on the album chart, and the band followed Rubin to his new label American Recordings for 1990’s “Seasons in the Abyss,” which reached No. 40 and kicked off with the Hanneman-composed track “War Ensemble,” which has since become a thrash standard.

Even as its contemporaries endeavored to adjust to the seismic changes wrought by grunge and alternative rock in the 1990s, Slayer maintained a traditionalist approach, endearing the group to legions of metalheads and high school outcasts through the decades. 1994’s relentlessly bleak “Divine Intervention” saw the band amazingly break into the top 10 of the album chart, peaking at No. 8, while 2008’s “The Christ Illusion” reached No. 5, and the group’s devoted following made it an evergreen live draw.

Hanneman was sidelined from performance due to contracting the flesh-eating condition necrotizing fasciitis from a spider bite in 2011. Exodus guitarist Gary Holt replaced him for several dates, though the change was always assumed to be temporary.

Hanneman is survived by his wife, Kathryn, to whom he was married since the 1990s, as well as his three siblings.