KNAC.COM air personality Junkman just checked in with the following sad news:

"Just got a call this afternoon stating that my friend, former Kiss guitarist Mark St. John, died this morning [April 5th] from a cerebral hemorrage. He was 51.

I have known him for a long time. I roadied for his band White Tiger, and just spoke with him at the recent NAMM show.

As soon as I fid out more info I will let you know. My heart goes out to his family. A very sad day.

Junkie"

Mark replaced Vinnie Vincent as lead guitarist for KISS in April 1984, following Vincent's falling-out with the band (Mark was suggested to Bruce Kulick was featured on the song, "Lonely Is The Hunter"). During work for the album, St. John clashed with the other members of the band, and eventually developed arthritis (Reiter's Syndrome), which caused his hands and arms to swell. He was all but unable to perform live as a member of KISS, and only played three (one in full) shows during the "Animalize" tour, with Kulick filling in for the rest. He was officially replaced by Kulick in December 8, 1984.

Source:	knac.com
Band profile:	KISS