The Cook County Medical Examiner's Office said autopsy results will be available Sunday afternoon. Kubiak said there's nothing to indicate foul play.
Welsh, 40, of Burlington, Vermont, performed with Weezer from 1998 to 2001, leaving after suffering a nervous breakdown, according to the band's website. He eventually established himself in a second career as a painter.
"I'm taking a break from music," he told MetroWest Daily News in 2002. "I really feel the need to reinvent myself and move on, and I couldn't be happier painting. Music is still an important part of my life, but I really have no desire to actually play it."
Weezer posted a message on its website, saying Welsh's time with the band was "vital, essential, wild, and amazing."
"A unique talent, a deeply loving friend and father, and a great artist is gone, but we will never forget him," the band said.
Welsh had planned to attend Weezer's Sunday performance at Riot Fest in Chicago.
"I'm excited to see the boys, hang out and have some fun," he wrote on his Facebook page earlier this month.
- Mikey Welsh
- Cook County Medical Examiner