A double fatality with children due to fumigated wheat

Two children, four and two years old, played on top of wheat, that had been fumigated with malathion, pyrethrum and phosphine. Both died within 18 hours. Because after the autopsy, death could not be attributed to any organic or violent cause, a toxicological analysis was carried out. No drugs, except alcohol, was detected. Those results were attributed to hydrolysis of malathion, yielding two molecules of ethanol. As this was an indirect proof of malathion ingestion, it was assumed that phosphine had been ingested as well and that consequently this was the cause of death, because it is much more toxic than malathion and because it was continuously generated from not completely dissolved aluminiumphosphide tablets, while the children were still playing.