Mikey Welsh, ex-Weezer bass player, was discovered dead in a Chicago hotel room Saturday (Oct. 8), according to several media reports and a post by his family on his Twitter account.

The Tweet stated, “We are deeply saddened to announce that Mikey Welsh passed away unexpectedly. He will forever be remembered as an amazing father, artist, and friend. May he rest in peace.”

Welsh, 40, was found by hotel staff after he neglected to check out of his room at the Raffaello Hotel. He was found unresponsive and on the floor at 2:50 p.m., according to the Cook County medical examiner's office. Welsh was in Chicago to watch Weezer’s performance at Riot Fest today.

Welsh played bass guitar with Weezer from 1998 to 2001, including the band’s famed ‘Green Album,’ which featured such hits as ‘Hash Pipe’ and ‘Photograph.’ Band members are understandably upset, and they turned to the web to express their grief over the breaking news.

“It saddens me and the guys in Weezer so much to say that our beautiful, creative, hilarious and sweet friend Mikey Welsh has passed away at the very young age of 40,” read a statement on Weezer’s official website.

“A unique talent, a deeply loving friend and father, and a great artist is gone, but we will never forget him. His chapter in the Weezer story (’98 – ’01) was vital, essential, wild, and amazing,” they added on their blog.

Welsh reportedly left the group after suffering a nervous breakdown, according to Weezer’s website.