The madness started when a Michigan school board treasurer named Andrew Kehoe killed his wife and blew up his farm with dynamite, which detonated simultaneously with explosives he planted at the nearby Bath Consolidated School. As rescue workers arrived on the scene, Kehoe showed he was playing for keeps by pulling up in a truck filled with even more explosives and blowing himself up, killing the rescuers as well. In total, 58 people were injured and 45 killed -- as many fatal victims as Columbine and Virginia Tech combined. All this, in a tiny village of 300 residents. He killed 1/6th of the population.
As crazy as this sounds, the massacre could have been a lot worse. Subsequent investigation found Kehoe had planted additional charges at the school, which he had planned to detonate as well. Tip to teachers: If you see a crazed man carrying massive amounts of dynamite around school grounds, maybe don't just offer him a casual high five and be on your way?
Bath School Museum
"You go talk to him."
"Hell no, you see how much dynamite he has? You tell him."
So, why did he do it? Apparently, he was upset about high taxes, losing the town clerk election, and, oh yeah, he was fucking nuts. Obviously, the U.S. invested heavily in mental health after the disaster, and nothing like this ever happened again.