What to do when someone dies?

The week before last my best friends grandfather died. It was something we were all kind of expecting but it was still a shock. I've known him since the eighth grade been to his house countless time and seen him be the kind patriarch of his family for years. So now knowing that he is gone is weird and I don't know what to say to my friend or how to really be there for her. I hope while she was home for the funeral I did what she needed. I still haven't had a death that has been close to me in my own family but losing her granddad kind of felt like it was. I have talked with him laughed with him spent holidays with him. I know him better than any of my three grandfathers. But at the same time he wasn't really mine so I don't feel like I have a right to be that sad. All I know is he was a great person and I will miss him and I know his family will to. I hope I don't experience a loss in my own family for many more years to come.