While rescuers were gathering at the school , Kehoe drove up , stopped and detonated a bomb in his shrapnel - filled vehicle .
A detonator Kehoe planted in the school ignited dynamite and hundreds of pounds of pyrotol .
While rescuers were gathering at the school , Kehoe drove up , stopped and detonated a bomb in Kehoe 's shrapnel - filled vehicle .
A detonator Kehoe planted in the school ignited dynamite and hundreds of pounds of pyrotol .