Once Upon A Time by Nadine Gordimer

Told in a fairy-tale voice, the story follows a white suburban family whose escalating fear of crime and outsiders leads them to fortify their home with walls, alarms, electric fences and razor wire; their obsessive pursuit of security, driven by prejudice and paranoia, tragically backfires when their young son is fatally caught in the booby-trap meant to protect them, exposing the corrosive, self-destructive effects of segregation and fear.