Just hours after Bob Weir shared the news bassist Rob Wasserman was battling serious health issues, comes word Wasserman has died. RatDog guitarist Mark Karan first revealed Rob had passed on with Weir confirming the news shortly thereafter.

Rob Wasserman is best known for his long tenure alongside Weir as a founding member of RatDog as well as the pair’s Bob Weir & Rob Wasserman project. Wasserman was a member of RatDog from the group’s mid ’90s formation through 2002 and then again from 2010 to their most recent performances. He also collaborated with a wide range of legendary musicians including David Grisman, Van Morrison, Neil Young, Aaron Neville, Lou Reed, Rickie Lee Jones, Metallica and Elvis Costello.

The bassist put out a trilogy of inventive albums starting with Solo in 1983 which he followed up with two-musician collaborations on 1988’s Duets and 1994’s Trios. “I’m devastated to pass along that Rob Wasserman lost his struggle today, and we have lost a beautiful friend and artist. I can still hear the sound of his bow playing those strings unamplified and pure. It’s one of the most glorious sounds I’ve ever heard, and the music and warmth he gave us will live on in the hearts of everyone he touched,” said Weir. Our thoughts are with Rob’s friends and family. As for now there is no word on the cause of death.

Watch Rob & Bob perform “Victim Or The Crime” in 1989: