Six workers were killed in the Columbin massacre in the United States. On 18 October, in order to achieve better working conditions, miners started a strike and managed to close almost all mines in Colorado.

However, a dozen mines, including that of Columbine, continued to operate with schirol. Outside this mine, an armed militia of exceptional police fired at the strike pickets and killed six workers.

The murderers did not have to respond to justice and impunity was imposed.