Today’s monstrous story of several students shot and at least one killed at an Ohio high school this morning has precedence — both in its brutality and its warning signs.

View Photo Gallery: A shooter believed to be a student opened fire Monday at Chardon High School outside Cleveland. The suspect, identified as T.J. Lane, is in custody.

The shooter, reportedly an outsider who had complained of being bullied, had apparently tweeted that morning that he would bring a gun to school. No one, apparently, took the tweet seriously.

As our kids continue to break down the boundaries between their real and virtual lives, parents and mental health specialists are debating whether and how to patrol social media postings for signs of kids in trouble.

Earlier this month, a New York Times story explored new research that showed, according to one study on a college campus, that about 30 percent of Facebook postings could be classified as indications of clinical depression.

The story said:

“ … specialists in adolescent medicine and mental health experts say that dark postings should not be hastily dismissed because they can serve as signs of depression and an early warning system for timely intervention. Whether therapists should engage with patients over Facebook, however, remains a matter of debate.

And parents have their own conundrum: how to distinguish a teenager’s typically melodramatic mutterings - like the “worst day of my life” rants about their “frenemies,” academics or even cafeteria food - from a true emerging crisis.”

It cited other tragedies foretold in public postings. One 15-year-old from Staten Island posted in December that she would try to end her life in a Facebook posting and a few weeks later stepped in front of a bus.

It also recounted a near miss. One mother checked her daughter’s Facebook update in time to read that her daughter had just swallowed “pills.” Relatives were able to reach the girl and rush her to the hospital.

The vast majority of the overly dramatic postings on Facebook and Twitter may be just that, but once in a while a real cry for help — or a real threat — lies in plain sight.

The question for experts and parents is how to tell the difference. And, how to tell the difference before tragedy occurs.

How much do you monitor your children’s public postings? How seriously do you take them?

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