Schools must also look within

A 49-year-old repairman from Northeast China's Heilongjiang province, whose employment contract with a primary school in Beijing's Xicheng district, was due to end this month, took revenge on the school, which refused to sign a new contract with him, by attacking students with a hammer when the pupils were taking their physical education class in the school playground on Tuesday morning. A total of 20 students were wounded, four of them seriously, according to a news conference organized by the Xicheng district government on Tuesday evening.

It is good that the district authorities in education, public security and medical care took part in the news conference presided over by the district head, and explained what had happened and what they had found in their investigation, as it helped to dispel public anxiety and nip rumors in the bud, as some social media posters were prepared to turn the breaking news into a sensational selling point.

Nevertheless, there are lessons to be learned from this tragedy.