Ace Frehley Remembered by KISS, Peter Criss, Paul Stanley After Death

KISS along with OG members Peter Criss and Paul Stanley are remembering Ace Frehley, the band's original lead guitarist, following his heartbreaking death Thursday.

Check out Peter's touching tribute shared on his website -- he confirmed he was with his "brother" along with his wife and Ace's family when he died peacefully in a hospital, where he had been on life support after suffering a brain bleed.

He also applauded Ace's legendary career, writing ... "As a founding member of the rock group KISS and in Ace's solo career, Ace influenced and touched the hearts of millions of people. His legacy will live on in the music industry and in the hearts of the KISS Army."

Paul, meanwhile, took to social media to share his favorite picture with his late bandmate and recall a fond story of his incredible guitar skills.

KISS -- which Ace helped form in 1973 with Peter, Paul and Gene Simmons -- said they are "devastated" by the loss, noting ... "He was an essential and irreplaceable rock soldier during some of the most formative foundational chapters of the band and its history."

Gene and Paul memorialized the iconic guitarist with the same statement to TMZ Thursday night as tributes from the rock world poured in.

We broke the tragic news Thursday -- Ace was hospitalized and breathing through a ventilator after taking a serious fall in the studio, which caused a brain bleed. His family took him off life support, after which he passed surrounded by loved ones.

Ace is the first original member of KISS to die. He was 74 years old.