I'm devastated. First the guy gets cancer at an early age, overcomes it, and then dies of a heart attack at 66? I played on two albums with him, and used to drive him to gigs, because he didn't have a car back then. I idolized the guy, and when he walked up to me and told me that he liked the way I play during one gig, I was on cloud nine.
Most guys that double don't master BOTH instruments, but he was frightening on BOTH clarinet and sax. As jazzbo said, he was a true 'keeper of the flame' as he showed on his many albums for Concord. What a great loss for jazz. RIP, Kenny...