A 4-year-old boy died after being locked in a school bus for nearly eight hours in Wuhan, Central China's Hubei province, on Thursday. Beijing News comments:

Last summer, four similar tragedies happened in North China's Hebei province within 15 days, which prompted the Hebei education and public security authorities to organize a sweeping campaign in the province to deal with the issue.

The negligence of the kindergarten staff, and the unprofessional management and poor supervision of the kindergartens were found to be the main causes of the tragedies.

There are regulations on school bus safety. Double-checking the number of children getting on and off school buses is a must-do for both school bus drivers and kindergarten teachers. Even if a driver's carelessness means there is a child on a bus, it should not be that difficult for the teachers to notice the child is missing from the class if they fulfill their duties. In the Wuhan case, if the driver's wife, who ran the kindergarten, had noticed the boy was not in class, his life might have been saved.

The central authorities should not wait for any more heartbreaking news to strengthen the supervision of kindergartens.

And it is suggested that all school buses be equipped with warning devices. For instance, if any safety belt buckle is still locked after the bus door is locked from outside, an alarm bell should ring. There should also be alarm buttons on the bus accessible to children. And learning to use the alarm buttons should be their first kindergarten lesson.

This may involve the problem of cost, but the problem can be easily solved by means of linking school bus safety with the school's certification and subsidizing school buses in rural areas.