Did you know him personally?
No, but you know if a celeb who's work you liked died and died a heck of lot younger than they should have done it's still sad and it affects you on some level. Not as much as someone you knew intimately did (like a friend or family member) but it does and sometimes it's nice to share with others who feel the same way. I kinda had that day in the days before twitter and facebook gave you more of an immediate connection or at least the illusion of one although I severely doubt that the celeb I mourned would have been on social media - I wouldn't knock fans of anyone for feeling sad that they've gone (I even felt sorry for Whitney Houston fans and loathe her music on the whole) and yes it is a tragedy. Neil Young in his song "The Needle and the Damage Done" described addicts as being like setting sons and I think that applies here.
I'd like to ask you if you've ever faced the sad news that an artist who meant something to you ever died young and if so did it really mean nothing to you - seriously?