The news was confirmed on Haskell's official Facebook page, though few details were given.
"It is with great sadness we announce the passing of Gordon, a great musician and a wonderful person who will be sadly missed by so many," a statement read.
Haskell first collaborated with King Crimson on the song "Cadence & Cascade." He was later asked to join the band full-time.
According to a memorial post for him on the Crimson website, "The experience was not a happy one for Gordon and he bitterly regretted his decision to join."
Fripp, meanwhile, simply wrote: "Fly well, Gordon..."
Outside of his work with King Crimson, Haskell enjoyed a robust solo career. Most recently, he released the solo album The Cat Who's Got the Cream earlier this year.
It is with great sadness we announce the passing of Gordon, a great musician and a wonderful person who will be sadly missed by so many.Posted by Gordon Haskell on Sunday, 18 October 2020
Gordon Haskell's Facebook page is reporting that Gordon has died. His time in KC wasn't a particularly happy part of his...Posted by King Crimson on Sunday, 18 October 2020