I'm at a loss for words on this subject, all I can express is grief. It has been easier to explain the death of our kitten to a hit-and-run; the death of the great-grandparents to old age; the freak accident of a family friend. It is complicated but possible to confront disease in the elderly. But when we visited the children's hospital recently when our infant was hospitalized (RSV), we were assaulted by the reality that not all children simply ...grow up. Many children suffer for a very long time, and still die. There is nothing fair about it. But as parents we're told not to talk to children like they are our friends...and all that comes naturally is tears and a lot of "I can't explain why things are the way they are, or what happens after these children die. I wish I could."
I wish I could. I was wondering what other people, atheists like myself, do.