The boys were all brothers or cousins aged 9 to 13. Surnamed Tao, they were the sons of three brothers — two of whom are migrant workers with jobs far from home — and most of them lived largely unsupervised in the care of their blind grandmother.

They had been missing for more than a week when, police say, they lit a fire to stay warm on a cold, damp night Nov. 15 in the city of Bijie and died from carbon monoxide poisoning.

As details of the tragedy emerged this week, it touched off the country’s latest soul-searching about social responsibility. It renewed concern over the “left-behind” rural children who are often left with grandparents while parents seek work in thriving coastal cities, and the failure of the country’s social services to adequately care for them.

“Though you departed from us in a garbage bin, you are not garbage,” children’s book author Zheng Yuanjie wrote in his microblog, adding that the fault lies with “adults who failed their responsibilities.”

Questions have been raised about how the children — found about 25 kilometers from their home village of Caqiangyan — could have gone missing for 10 days without more of an effort launched to find them. Six local officials, including two school principals, were sacked on Tuesday.

“We have failed in our management work,” said Tang Guangxing, a spokesman for Bijie city, where the boys’ bodies were found Friday. “Our work was not attentive enough.”

State media outlets, giving the deaths broad coverage, have joined in the hand-wringing.

“This is a shame that cannot be washed away by a civilized society,” the Beijing Youth Daily wrote in an editorial this week.

The official Xinhua News Agency said the boys had poor grades at school and had essentially dropped out of their classes. Xinhua faulted China’s education system for putting too much stress on academic excellence at the expense of caring for less successful students.

“Please do not forget the mission of compulsory education. Please spread love and responsibility like sunshine,” Xinhua wrote in an editorial. “This is also a tragedy of ‘left-behind children,’ which is a sign of the time and requires introspection from family, society and government.”

Many critics in China have fretted over decaying public morality as the country’s economy rapidly grows and its people enjoy unprecedented wealth. A similar outcry erupted last year when a toddler in Guangzhou was run over by two vehicles and then ignored by at least 18 passers-by.

The latest incident has focused concern on the plight of families in impoverished rural areas. An estimated 58 million children countrywide lack sufficient supervision or stay in the care of grandparents when their parents seek work in China’s booming cities.

Some details of the boys’ home life remain unclear. Their relatives lack telephones and could not be contacted, though some were quoted by Chinese media outlets who sent journalists to the extremely poor, mountainous region of mud huts where farmers earn about 3,000 yuan ($475) a year.

The boys — Zhongjin, Zhonghong, Zhonglin, Chong and Bo — were found in a 1.5-meter-by-1.3-meter (5 foot-by-4 foot) garbage container in Bijie after a night of drizzling rain when temperatures were about 4 Celsius (40 Fahrenheit).

Two of the fathers, ironically, are garbage collectors in the boom city of Shenzhen near Hong Kong, according to a Xinhua report. One of the mothers lives in Shenzhen and another reportedly left the family. The third brother and his wife are farmers in the Bijie area, though they apparently often left the boys to fend for themselves, Xinhua said.

Former journalist and Bijie resident Li Yuanlong posted online that the children had been spotted living in a temporary shelter with plastic cloth, bricks and plywood at a nearby demolition site.

Li, who broke the story on the deaths in an online posting, told The Associated Press on Wednesday that local officials in Bijie were not pleased with the coverage and that police there told him to leave the city for four or five days.

Some observers have faulted the family for not keeping closer watch over their children.

“How could grandparents take care of your child when you are away?” asked Beijing parking attendant Liang Hongjin, a migrant worker from Henan province.

However, much of the criticism has been directed at the government and educational system.

The family reported the boys missing Nov. 5. Beijing lawyer Li Fangping said the failure of local officials to launch a proper search was “horrific.”

The boys died hours after Xi Jinping gave his first speech as China’s new leader in Beijing’s Great Hall of the People. Xi underlined the Communist Party’s mission to improve the country’s education, employment, social security, housing and health care.

“Our people have an ardent love for life,” Xi said in the speech. “They want their children to have sound growth, have good jobs and lead a more enjoyable life.”

The boys’ death reflects a systematic failure of children services, Beijing Normal University social welfare expert Wang Zhenyao said on state-run China Central Television. The system lacks shelters, social workers and volunteers, and there is poor communication with those in need, he said.

“That’s a blank in China,” he said.