Nancy:
Those things are never easy but kids look at death differently than we do. If you are calm and not frightened, your son will be calm. From personal experience:
When my son (Ghost) was 4 years old, my father passed away unexpectedly and suddenly in Europe. It was in August. My kids and I have spend 7 weeks visiting my parents at the beginning of summer, so the memories of Grandpa were fresh in their minds (my daughter was 2 at that time). I took my kids and we flied to Europe again, attended the funeral and spend another month helping my mom adjust to the new situation. Before the funeral I could not bear myself to go to the funeral home and see my dad in the casket. I wanted to remember my dad alive, I wanted to remember this last hug he gave me at the airport before my flight to Paris... I stayed outside with my two year old who was to whiny to go inside at that time. But my 4 year old wanted to go and see Grandpa in his casket. He still remembers all about it - he is 12 now - and never had any bad dreams or anything like that after that. I honestly believe that if you listen to your child and not hide anything from them, they are able to "grow' to the situation.
Death is a part of our lives and we should not protect our kids from it. If we treat death naturally our kids will do the same thing. Grief is a part of growing up. I found out about my father's death via a phone call at 2 A.M. You can imagine how shaken I was when I woke up Ghost the next morning. And he sensed that immediately, but I was frank with him. I was shocked at my father's death and it was OK to mourn.
Last spring my father in law passed away. He had leukemia and we were expecting it. Even though, when Ghost spoke to him over the phone for the last time, he told him to please hold on until the summer so they could see each other for the last time. I thought it was beautiful...He died before Ghost could fly to see him...
We went over the summer and visited his grave. My both kids were absolutely OK with the fact that he had died...
I am an oncology nurse and frequently I bring home stories about my patients, so my kids do hear a lot about dying. The only advice I have is BE HONEST. Do not hide anything for the fear of hurting your kids. It is the lies about death that will hurt them. But remember, it is never easy because we project our own experiences upon our kids. So relax and let your son choose what to do next. You won't regret that decision... And do pray for this uncle with your son if you are religious, it helps bring perspective to everything we do.
Ania