Sad Day

I just found out that Randy Pausch, the professor from Carnegie Mellon University, has died. He is the professor that wrote the book "The Last Lecture". I am sad because I think of his kids, two of them are the ages of my kids. I can't imagine not being there for my kids as they are growing up. How do you explain to a one year old and a two year old that their parent is no longer around. I don't even want to think about it because I just get teary eyed. My sympathy goes out to the Pausch Family.