"For kids, how they perceive death depends on their age and cognitive development. Preschool aged kids believe death is temporary. Five to nine year olds start to realize that death is irreversible and that all living things die, but think that they are somehow immune to it. Preteens, however, fully comprehend death. "Between 9 and 12, children understand that death is inevitable and affects everyone," explains Dr. Jessica Lippman, author of Helping Children Cope With the Death of a Parent."