Don't make the mistake of thinking just because they don't say anything, that everything is all right with them, or that they don't care. Talking to children about serious issues that have upset them is an ongoing process. It's not a one-shot deal. Once you talk about something that is bothering a child, whether it's about a loved one in the military or someone dying, it's not over. You have to revisit these issues every now and then.
Parents sometimes worry about what to say to a child.
Try practicing with another adult or read materials that address this problem. The World Wide Web site has parent resources, including links to publications and other information. Another good source of information is books. There are all kinds of books that talk about what you can say to children about serious issues. If you don't have time to read a long book, look for children's books.