Include children in the clean up process. Let the children be responsible for as much of the clean up process as they can handle. By seeing that it is possible to return to a normal life, children will realize that the world has not come to an end. As they are helping, encourage them to talk about their feelings. Allow children to make some decisions regarding the family.
Children can decide where and what to eat, or how to lay out family sleeping bags in the shelter.
This will help them feel that they still have some control over their lives. Leave time for play. Children need to be children even in disaster and need to have time to escape from the demands of the disaster. Encourage children to play, and help them find things to do. Your local community will generally provide play materials in shelters.