That is a comforting thought for a nation scarred and grieving. But viewed through the prism of science, it isn't necessarily true. The cold, hard reality of the deadliest school massacre in American history is that it was the statistical equivalent of a needle in a haystack. Because such events are so rare, and because it is impossible to eliminate risk from life, there may be no larger lessons to draw, and no way to prevent another one. Consider the numbers.
Homicide is the second-leading cause of death among youngsters.
They are so rare, and there are so many school kids, and our understanding of what motivates people to be violent is so imprecise, that this would be a very difficult task. Still, there is the impulse to analyze, to understand, to prevent. After disasters like Littleton, where two teenage gunmen killed 13 people and then themselves, sociologists, psychologists and criminal justice experts are interrogated by the media in a collective search for societal failures, in much the same way that aviation investigators look for jammed rudders or ruptured fuel lines after an airplane crash. But risk cannot be eliminated. Fine surgeons still kill patients.