Steve Soto, bassist and founding member of California punk band the Adolescents, died last night at the age of 54. The cause of death is currently unknown.

Soto’s bandmate Tony Reflex confirmed his death today in a tweet: “with heavy heart i share the passing of steve soto, my friend and bandmate since 1979. i dont know what to do. or to say. goodbye my brother.”

Soto recently wrapped up a tour with the Adolescents in Boston. He and the band had been preparing for a summer tour and the release of their new LP Crop Duster.

Before the Adolescents’ inception in 1980, Soto co-founded the pioneering surf-punk band Agent Orange. Listen to some of Soto’s best below.

with heavy heart i share the passing of steve soto, my friend and bandmate since 1979. i dont know what to do. or to say.

goodbye my brother.

— The Adolescents (@TheAdolescents) June 28, 2018