L.H.
Dear Lorelei... You have such a wonderful heart. Your son is blessed to have such an awesome Mom. I lost someone at an early age and I was devastated to learn someone MY age could actually die! We made a card for his family. WHile that was polite, I now understand it helped me deal with my feelings, as well. I feared I MIGHT DIE just like my friend. (Thankfully we discussed it and I realized this was just something rare as this was the only child around me who ever died and all of my friends were still with me.) Seeing his parents cry taught me that they were also dealing with an unbelievable hurt, too. And I learned to see beyond myself at an early age.
As to what to tell him... I wish I'd been told that some people are only here on Earth for a short time. That sometimes God answers a prayer for wellness by bringing them to him to stop the pain and sickness they are feeling. That he'd be missed by all who knew him but that his purpose for being here with us was done and that God had a special job for him in Heaven. That, he'd never be forgotten and that one day, I'd see him again when I went to be with God when I was old and took my last breath. Hearing the "when I was old" would have really helped me.
I DID learn about Heaven at an early age which has always given me something to look forward to! No more tears, sickness or anything negative! And that GOD will care for his friend should give him great comfort...
Expect him to be tired and out of it. Give him breaks. Let him talk to you about it or draw pictures. He may need a night light or more of your time at bedtime. CUDDLE him even more than normally! Watch him for signs and let him lead your discussions when HE needs to talk.
I will be praying for you and the child's family. GOD be with you! L.