Although I'll miss my grandfather, his passing really isn't sad or tragic.
He was 90. He was active until he collapsed and was only in ICU for a week. At the end of his life, he was being reassured by my mom that we were all ok and that we'd take care of Grandma.
Since we all have to die, it seems to me that his life and death were the best possible scenario for him. It would have been much more tragic for my grandfather to have lived, but with significant physical or intellectual limitations. He would have been a burden on his children (especially Super-Mom) and his beloved wife -- and although he was cantankerous, he wouldn't have wanted that to happen.
I suppose my take on all of this is skewed because I'm comparing it to other deaths -- my father died when he was 48 and I was 13. My only sister died when she was 30 and I was 33. Both of their deaths were sudden and unexpected -- and I'd put them in the "tragic" category.
So, I suppose when you can honestly say that a person had a long and happy life, that they leave behind a family with good values and who will probably make their corner of the world a better place, and that their passing wasn't long or painful -- it isn't sad or tragic -- it's just life.