A tragedy that occurred in Shangrao, Jiangxi province, on Friday, in which a man stabbed a 10-year-old boy to death in the classroom of a local primary school, has once again shed light on a perennial problem that schools are facing: how to better protect students from potential dangers.

The man stabbed the boy in broad daylight, in front of all other young students, apparently because he believed the boy had bullied his daughter many times.

So far there has been no official statement from the police supporting that claim, but his WeChat conversations with the boy's parents prior to the incident were leaked online, and in these he expressed anger over what he presumed was the boy's bullying of his daughter.

No matter what his grievances might have been, his cold-blooded murder of the youngster must be condemned in the strongest possible terms by all people, and he must face the legal consequences.

Yet strangely, the murder suspect has gained sympathy from some internet users, who said that the man was just giving a lesson to the "bully" that his parents and the school teachers had failed to deliver.

Such a distorted sense of justice reflects the ignorance and callousness of some in our society. Their irresponsible remarks have mocked the rule of law, and rubbed salt in the wounds of the victim's family members.

A police investigation is still underway, and it is too early to conclude if anyone else should shoulder some of the blame for the tragedy apart from the suspect killer himself.

But the facts available suggest there are a lot of lessons that can be learned, especially because the incident has exposed the poor judgment and lax management of the school.

The teachers failed to discern the dispute among the students in the first place and, even after it came to light, as the WeChat conversations suggested, they failed to take preventive measures, for example, by arranging for a meeting between the parents and the school, on the excuse that they found it "difficult to communicate" with the girl's father.

After the murder suspect had threatened to solve the problem his own way, the school, rather than report the case to the police, or take additional security measures, only asked the boy's parents to escort him to school as a precaution. The boy's father did exactly as the school required, but still could not prevent the boy from being killed.

There are always people out there ready to inflict the biggest possible harm on the weak and the vulnerable, mostly minors in schools, either to vent their anger or as a means to retaliate against society for some injustice that they presume they have suffered. Schools have a responsibility of care and must act to protect the kids from any foreseeable dangers.

Hopefully the latest case in Jiangxi could serve as a wake-up call for those schools that are yet to maintain the highest alert against possible threats to their students.