Children at an early age instinctively trust their parents. As the children grow, parents should work to develop their child's trust in God. God is sovereign and omnipotent. Children should learn to trust Him in their lives and depend upon Him to watch over them and keep them safe. Discuss the reasons for pain and suffering in the world.
Bad things do happen to good people.
Teach vigilance without hysteria. We need to balance our discussions with them and not make them hysterical. Kids have been known to become hysterical if a car comes down their street or if someone looks at them. Work to establish broadcaster guidelines. No TV or movie producer wants to unilaterally disarm all the actors on their screens out of fear that viewers will watch other programs and movies.