M.L.
My father died of very long and difficult battle with Leukemia when I was 22, he was only 49...so I have been raised around dealing with mortality. And just last week, both my great-grandmother (who was 95) and my husband's grandmother (who was in her 70's) died.
It is a hard thing to think about, but when an elderly person dies, I think about how lucky they have been to live such a long and happy life, filled with the things that are most important, a family that loves them and supports them. Also, many of them are tired, often times lonely, and ready to come to that peace also known as death.
Instead of dwelling on the inevitable, gather the family around and celebrate what he has left. Make a slideshow of his life, write down his history and genealogy, stories of his boyhood and reflections on life and seeing the world change. They will be so valuable when he is gone. And one day, you will all meet again on the other side and can speak of this time as not one of goodbyes, but of happy memories being made.