The Bath School disaster is the historical name of the violent attacks perpetrated by Andrew Kehoe on May 18, 1927, in Bath Township, Michigan, that killed 38 elementary school children and six adults in total, and injured at least 58 other people. Kehoe first killed his wife, fire-bombed his farm and set off a major explosion in the Bath Consolidated School, before committing suicide by detonating a final explosion in his truck. It is the deadliest mass murder in a school in United States history.
Andrew Kehoe, the 55-year-old school board treasurer, was angry after his defeat in the spring 1926 election for township clerk. He was thought to have planned his "murderous revenge" after that public defeat and he had a reputation for difficulty on the school board and in personal dealings. In addition, in June 1926 he was notified that his mortgage was going to be foreclosed. For much of the next year, a neighbor noticed Kehoe had stopped working on his farm and thought he might be planning suicide. During that period, Kehoe purchased explosives and discreetly planted them on his property and under the school.
Kehoe's wife was ill with tuberculosis, he had stopped making mortgage payments, and he was under pressure for foreclosure. Some time between May 16 and the morning of May 18, 1927, Kehoe murdered his wife. Then on the morning of May 18 at about 8:45 a.m., he set off various incendiary devices on his homestead that caused the house and other farm buildings to be destroyed by the explosives' blast and the subsequent fires.
Almost simultaneously, an explosion devastated the north wing of the school building, killing 36 schoolchildren and two teachers. Kehoe had used a timed detonator to ignite hundreds of pounds of dynamite and incendiary pyrotol, which he had secretly planted inside the school over the course of many months. As rescuers began working at the school, Kehoe drove up, stopped, and used a rifle to detonate dynamite inside his shrapnel-filled truck, killing himself, the school superintendent, and several others nearby, as well as injuring more bystanders. During rescue efforts at the school, searchers discovered an additional 500 pounds (230 kg) of unexploded dynamite and pyrotol connected to a timing device set to detonate at the same time as the first explosions; the material was hidden throughout the basement of the south wing. Kehoe had apparently intended to blow up and destroy the entire school.