Forensic tests have explained why so many kids at a rural school in India died so quickly after eating lunch: The agricultural pesticide found in their food was five times more powerful than usual, reports the Wall Street Journal. Police bought a bottle of pesticide containing the chemical compound monocrotophos—the killer ingredient in this case—and compared it to the levels found in the students' food. "The intensity of the chemical in the meal was five times higher," says the local police chief. "Even if you smell the fumes of such a chemical it can be fatal. In this case, the children had eaten it."
So how on earth did it get in there, resulting in 23 deaths? That remains under investigation, though police have speculated that cooking oil used in the meal had been stored in a container that used to hold the pesticide, reports Reuters. They'll know more assuming they ever catch up with the still-at-large school headmistress. She reportedly dismissed complaints from the cook and the children that the food smelled horrible. The World Health Organization considers monocrotophos "highly hazardous," and the EPA says it is no longer used in American products.