An 8-year-old boy died at a hospital in the western Mexican state of Jalisco after falling into a contaminated river and being poisoned with a substance that could be arsenic, Mexican media reported Friday, according to DPA. The boy fell into the Santiago river, in the municipality of El Salto, on January 27. He was rescued from the water, then spent 19 days in a coma before his death. The autopsy carried out by the Jalisco Institute of Forensic Science confirmed that he died of damages caused by a chemical agent yet to be identified. A previous study had revealed that there was arsenic in his bloodstream.