The understanding of children at this age is closer to that of an adult, although they may find the abstract nature of faith or less concrete concepts hard to understand. Like younger children they will need specific questions answering and find detail important. They may become more anxious about their own mortality and those around them.
It is important to listen to and acknowledge their concerns, and to put them in a realistic context.
It can help children to practise answering questions they may receive from other children, with information they are comfortable with.