A boy was dead because of drunk l-methadone by mistake

In Hunan of China, an eleven-year-old boy mistook l-methadone as water to drink, ignorant grandparents send him to hospital after a few hours when the boy in lethargy. The boy is dead now.
On the night of July 4, the boy who stay at grandmother’s home feel thirsty, he opened the refrigerator, take out a bottle of mineral water, drunk the water in one gulp. This bottle of water which his uncle brought out from the rehabilitation is l-methadone (LookChem). When found no reaction after drunk l-methadone, grandparents didn't care about that.
At two o 'clock in the morning, the grandma go into the room and found sleeping boy looks no good. His lips and skin is black, and he can’t speak. the child was rushed to the hospital. But the treatment time has passed, the boy will be sleeping for ever.