Point out to your child that your family has a memorable past, a worthwhile present and a hopeful future. Point out that your family is not faithless or simply angry at everybody. Point out that all of you in the family have a conscience. These are all causes to rejoice. Most importantly, don't take a normal child with normal fears to a therapist over this matter .
Behaviors Bringing Closure Go for closure.
It is OK for your child to attend a memorial service. It is OK for your child to hang out with their friends and discuss it. However, don't make it an eternal discussion for days on end. Bring some closure to it. Get on with the business of being a child, being a family, being a student and being a parent.