Founding Monkees bassist / vocalist Peter Tork has died at 77 years old. No official cause of death has been announced, but Tork was a cancer survivor, being given the all-clear in 2012 after being diagnosed with a rare form of tongue cancer three years prior.

Along with Davy Jones, Micky Dolenz and Mike Nesmith, Peter Tork became extremely famous after the Monkees TV show debuted in 1966. Tork left the group in 1968, but would do on-and-off touring with the Monkees from 1986 to 2016.

Tork’s death was announced by his official Facebook page earlier today (Feb. 21):

It is with beyond-heavy and broken hearts that we share the devastating news that our friend, mentor, teacher, and amazing soul, Peter Tork, has passed from this world. As we have mentioned in the past, the PTFB team is made up of Peter’s friends, family and colleagues – we ask for your kindness and understanding in allowing us to grieve this huge loss privately. This page will remain open for your use in sharing your thoughts with your fellow fans and hopefully helping you through your own grieving journey, however the team will not be available for some time as we start to mend our own hearts and calm our minds. We want to thank each and every one of you for your love, dedication and support of our “boss.” Having you in our world has meant so very much to all of us. Please know that Peter was extremely appreciative of you, his Torkees, and one of his deepest joys was to be out in front of you, playing his music, and seeing you enjoy what he had to share. We send blessings and thoughts of comfort to you all, with much gratitude ~ptfb team

Michael Nesmith paid tribute to his bandmate on Facebook:

Pardon me if I am being dogmatic -- but I think it is harder to put together a band than a TV show -- not to take anything away from TV shows. These days I watch MSNBC -- mostly aghast at what I see -- and what I am missing is "madcap".

Peter Tork died this AM. I am told he slipped away peacefully.

Yet, as I write this my tears are awash, and my heart is broken. Even though I am clinging to the idea that we all continue, the pain that attends these passings has no cure. It's going to be a rough day.

I share with all Monkees fans this change, this "loss", even so.

PT will be a part of me forever. I have said this before -- and now it seems even more apt -- the reason we called it a band is because it was where we all went to play.

A band no more -- and yet the music plays on -- an anthem to all who made the Monkees and the TV show our private -- dare I say "secret" -- playground.

As for Pete, I can only pray his songs reach the heights that can lift us and that our childhood lives forever -- that special sparkle that was the Monkees. I will miss him -- a brother in arms. Take flight my Brother.

Micky Dolenz tweeted about his sadness over Tork’s passing:

Tork is the second original Monkees member to pass away, as Davy Jones died from a heart attack in 2012.