About when I was seven, having been shown films of Hiroshima and Nagasaki as the bombs exploded and the aftermath, with sirens blowing we were instructed to hide under our desks. Having seen those films, we had little or any faith that hiding under our desks was a solution. We had already learned radiation can kill and couldn't be seen, traveling with the sunlight as it passed through windows. Boys being boys, mass killings weren't on our minds, or thoughts of our own mortality, but we did start passing knowledge of the different colors of the girls underwear, spied as we were under those flimsy desks, and all the girls were required to wear skirts, as boys were required to wear neckties. Clip-ons were prevalent, as were yellow and pink panties with flowers.
The general consensus, tho we didn't know the word, true fear formed in the presence of older bullies, old Mrs. McGovern who taught kindergarten, getting sent to the principal's office, "wait till your dad gets home," and nasty older sisters. Death and the bomb were still too abstract, but under the desk drills ameliorated the boredom of sitting at the desk forbidden from speaking with each other, even tho most had already experienced goldfish and parakeets getting flushed down toilets.
Things are different. TV has made for more sophisticated kids, kids who don't laugh at rabbits beating up pigs, or the Three Stooges smacking each other around. There was rape and abuse, not spoken about, and headlines of gangland murders with blood on the front pages of B&W tabloids. But we weren't gangsters (yet), just kids. And in all the movies and TV shows the bad guys got theirs from the heroes who rode off in the sunset.
Later those same kids, a bit more sophisticated, taking to heart earlier lessons about morality, embraced the counter culture, anti bomb protests, anti war protests and free love, equality to the shock of the older generation who taught them those values.
For the most part we all want the same thing, to live well, see our children and grandchildren prosper, live without fear, without suffering. Yet there are predators out there, people who enjoy killing people. That's the story of Cain and Abel, from the dawn of time with no explanation, just admonishment.
When we speak to survivors of these incidents, one phrase echoes in the background "I never thought it would happen here." That sense of suspended disbelief is no longer extant. As long as the human race continues to produce predators, there will never be a moment where "enough is enough." Every time someone labels someone else with a derogatory term, the fires of hate are stoked, the predators are fed and nourished. Happens here everyday.