BEIJING — On the day China unveiled its new leadership in Beijing with promises of a better life for all, five runaway boys died in a garbage bin where they had sought shelter and warmth on a cold, damp night in the south.

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 the night of Nov. 15 in the southern city of Bijie and died from carbon monoxide poisoning.