Bath school disaster, pair of bombings on May 18, 1927, of Bath Consolidated School in Bath Township, Michigan, U.S., that killed 38 schoolchildren and five adults. The perpetrator also killed himself.
The man who carried out the attack, Andrew Kehoe, spent months before the event placing dynamite and the World War I explosive pyrotol under the flooring of the school. He murdered his wife a day or so before May 18. On the day of the massacre, he used rigged explosives to destroy the buildings of his nearby farm moments before the explosives in the school were detonated by an alarm clock at 9:45 am.
The north wing of the school was destroyed in the explosion, and 36 children and 2 teachers were killed (another child died nearly a year later). Approximately half an hour afterward, Kehoe drove his truck to the school. The back seat of the truck was loaded with metal debris piled on top of dynamite, and Kehoe fired a rifle into the back seat when he arrived at the school. The truck blew up, killing Kehoe, the school superintendent, two other adults, and a child who had escaped the school bombing.
Rescue workers searching through the rubble of the school later found some 500 lbs (230 kg) of explosives in the south wing that had failed to detonate, suggesting that Kehoe had intended to destroy the entire school.
https://www.britannica.com/event/Bath-school-disaster-1927