Even as Eric Harris and Dylan Klebold roamed the halls of Columbine High, the questions began. What did it all mean?

Perhaps nothing. Littleton's tragedy was hardly random violence. Rather it was the culmination of a yearlong plan organized by two nihilistic, near-adults who worshipped Hitler, despised their peers and indulged their dreams of Armageddon. Indeed, as more information is unearthed and it becomes more and more evident just how bizarre both men were, it seems increasingly odd that no one intervened before last week's assault.

And so Bostonians, holding their collective breath for fear that Littleton was a plague that could just as easily strike close to home, are now starting to relax. Colorado is, after all, far away and far different.

But don't relax too much. Events like Littleton are perhaps so rare as to seem sui generis. The truth is, it is extraordinarily unlikely that Boston will ever see a replication of the Littleton slaughter. Far more common, and truly far more troubling, is the everyday, casual violence that wracks our high schools.

Last year there were 1,258 crimes committed in Boston's public schools. This year that number is expected to climb by 20 percent to 1,506. While crime throughout the rest of the city has declined, it is going up in the schools.

The school system sanitizes these events, calling them "violations of Massachusetts General Laws." But make no mistake, they are crimes. Four hundred and thirty of those crimes — 28 percent — are assaults and batteries. Most of the rest involve theft or property damage or abusive and violent behavior. Interestingly enough, only 42 incidents— a scant three percent — involve illegal drugs.

It's a safe bet that most if not virtually all of these crimes occur in the city's 27 high schools. That works out to 56 crimes a school, about 1½ crimes a week in each school.

Is it any wonder so many kids fear school? It's not the prospect of tomorrow's quiz that scares them, it's tomorrow's beating.

In the wake of Littleton, we will undoubtedly see demands for stepped-up security: metal detectors, harsher rules on knives and guns, random searches of lockers, the stop-and-frisk of students.

Indeed, Boston already does some of this. The Burke High School in Dorchester has metal detectors. It reputedly takes about an hour each day for students to file into the building. Other schools also have detectors. Some use them, some do not. A number have concluded that things like metal detectors have a perverse consequence; they implicitly say to our children that we expect them to be bad.

Littleton will undoubtedly be our collective focus for the next several days. Meanwhile, the everyday crimes that are so much the stuff of the ordinary school day will not be discussed, remarked on, or analyzed.

Coloradoans are now wrestling with an awful question: Why didn't we see it before it happened? Boston probably has little to fear from apocalyptic events like Littleton. But like Littleton, maybe we too need to start paying attention to our children.