This certainly is a horrible tragedy, and my prayers are with the victims and their families.
School tragedies are not an invention of modern times. The worst one happened in Bath, MI.
On May 18, 1927, 45 people, mostly children, were killed and 58 were injured when disgruntled and demented school board member Andrew Kehoe dynamited the new school building in Bath, Michigan out of revenge over his foreclosed farm due in part to the taxes required to pay for the new school.
