In a coma, on a ventilator after a coronary event of some type. Family at his side, apparently his passing is imminent. Leslie was of course best known for his work in Mountain and West, Bruce and Laing. The remarkable tone he got out of that most basic of electric guitars, the single pickup Les Paual Junior, made a big impression on many noted guitarists (excerpted article below from Blabbermouth music site)
Born Leslie Weinstein, West first gained worldwide recognition in 1969 as the guitarist and singer in the groundbreaking rock band MOUNTAIN. Included among Leslie's many fans and disciples are six-string luminaries such as Eddie Van Halen, Randy Rhoads, John McLaughlin, JETHRO TULL's Martin Barre, Warren Haynes and Ritchie Blackmore of DEEP PURPLE. Blackmore has stated that Leslie's phenomenal playing on "Mississippi Queen" served to redirect the course of DEEP PURPLE's music in an instant, ultimately resulting in the brutal hard rock intensity displayed on "Deep Purple In Rock".
For Barre, meeting Leslie in 1970 served to inspire the writing and playing on JETHRO TULL's most successful album in the band's history, "Aqualung". "Prior to going into the studio to record [1971's] 'Aqualung', I met Leslie, whose playing I absolutely loved," Barre revealed. "Leslie is well known for his association with Les Paul Juniors, and just after meeting him, I picked up a 1958 Junior because his sound was so incredible. I would say that he's the only guitarist who has ever influenced me directly."