sentences:  During the 1913–1914 United Mine Workers of America strike against the Rockefeller-owned Colorado Fuel and Iron company–an event known as the Colorado Coalfield War–the Guard was deployed in October 1913, again under the command of Chase.The Guard was involved in several violent encounters prior to the 20 April 1914 Ludlow Massacre, in which over a dozen women and children were killed when Guardsmen fired into a tent camp at Ludlow.Following the massacre, the Guard battled strikers throughout Southern Colorado during a 10-Day War.