The Columbine Mine massacre occurred in 1927, in the town of Serene, Colorado. In the midst of the 1927–1928 Colorado Coal Strike across the state, workers had been picketing one of the few remaining operating mines, in Serene. 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.