3 boys preparing to kill the principal.... Oh the the wonders of our child abuse laws. These three probably could have used a good swat on the behind way before they entered first grade. No discipline or yelling only is contributary to some of these children without social skills.
Chemicals disbursed in the air and not harming anyone is a clearcut "got away with it" by the chemical plant. If years down the road people come down with ailments, they will deny it ever happened or that it was contributory to what symptoms people have. Might be good to document what chemicals were released and the federal agency to which the accidental release was reported. If they didn't, you can.