During a two year span when I was in one band (between 1979 and 1981 - before Spinal Tap), we had one drummer first get hit by a car walking across his street, then a second car hit him and decapitated him. We had another drummer who went the same way that Bonham did (choking on his own drunken puke). Then a third who got depressed after his girlfriend broke up with him (during one of our backyard, kegger party gigs), went home and overdosed on pills and vodka. A fourth quit because he wanted to play keys like his dad (Doug Ingle - son of the Iron Butterfly drummer - and still alive!).
Another drummer that I went to high school with (Mike Grove) and who I later played in a band with for six weeks (in late 1984) apparently died not long after the band broke up, but I don't know how. When our lead guitarist (Craig Goldy) went off to start Guiffria, Mike went to play drums for Mickey Ratt (which later became Ratt). I never heard of or from him again and it wasn't until a website was set up for one of the high school reunions that I learned he had passed away the next year.
I quit playing in bands before having one spontaneously combust however, which is a good thing since going that way could damage our gear you know.