Lou Koller, frontman and co-founder of New York hardcore band Sick of It All, died at age 59 after a two-year battle with cancer.

The band announced Koller’s death in an Instagram post, describing the loss as overwhelming" and remembering him as a beloved friend and an iconic frontman.

The group said Koller's camaraderie, commitment and enthusiasm were always steadfast throughout the years, adding that Lou had the power to raise everyone’s spirits at our shows with a smile and a sarcastic comment, and he won people over wherever we played, from every culture and every corner of the world.

Fans and fellow musicians rallied around the singer, raising money for his medical expenses through a benefit concert at Irving Plaza in New York later that year.

In May 2025, Koller announced he had completed his final round of chemotherapy and had been declared cancer-free, but months later revealed the cancer had returned, the New York Post reported.

Born and raised in the New York City borough of Queens, Koller co-founded Sick of It All in 1986 with his younger brother, guitarist Pete Koller, and drummer Armand Majidi. Speaking to Anti-Matter in 2024, Koller credited his upbringing for shaping his outlook, saying, That's the way we were raised in our neighborhood in Queens. You didn't go out looking for trouble.

Sick of It All became one of the defining bands of the New York hardcore scene with the release of its debut album, Blood, Sweat and No Tears, in 1989. The band released 12 studio albums over nearly four decades, including Scratch the Surface in 1994 and Wake the Sleeping Dragon! in 2018, while building an international following through relentless touring, according to the New York Post.