Columbine Mine massacre: Striking coal miners are allegedly attacked with machine guns by a detachment of state police dressed in civilian clothes.
The Columbine Mine massacre, sometimes called the first Columbine massacre, occurred in 1927, in the town of Serene, Colorado. A fight broke out between Colorado state militia and a group of striking coal miners, during which the unarmed miners were attacked with firearms. The miners testified that machine guns were fired at them, which the state police disputed. Six strikers were killed, and dozens were injured.