Touring is hard, doing drugs is hard, the stress of putting out good enough material to not get dropped by your label is hard.. Most musicians I know don't take care of themselves, at all.. they're too lazy..
It sucks, but not always surprising - to me, anyway.. the real barometer of musician death will be when Keith Richards passes, although I think he will easily outlive me..
Friendship is like peeing your pants.. Everybody can see it, but only you can feel the warmth..