Research has found children want more information then adults usually give them. To fill in gaps in their knowledge children will use ways to find out without actually asking questions. Children may watch others like their parents. They may eavesdrop on adult conversations to find out more.
Children create their own meaning from the information they find. They will use this to try to fill in the “missing pieces” themselves. So when adults try to reassure children it may not work because children have their own knowledge. Children are thinkers so reassurance without real talking does not usually work as well as adults think.
It also helpful to find out what questions a child has about a death of a loved one. Answers should give a good answer to their question but worded for the age of the child. Adults may also use another loss related to death as a springboard to explore spiritual questions and to openly discuss death and dying with children. These are usually better than simply giving answers to assumed questions and "reassurance".