Mikey Welsh, most famously known as the bassist for the rock band Weezer, died unexpectedly Saturday, according to the band. He was 40. The cause of death was not immediately known.
Welsh was part of the band’s 2001 “Green Album” release, which featured “Hash Pipe.” The single became one of the band’s biggest hits, peaking at No. 2 on Billboard’s Alternative songs chart.
Welsh left the band shortly after, saying he had suffered a nervous breakdown.

