Today in Labor History June 22, 1914: Anarchists, intending to bomb the Rockefeller Mansion, accidentally blew up the Ferrer Center for anarchist education, killing three anarchists and putting a temporary end to the Modern School. They had been seeking revenge against Rockefeller’s Standard Oil for the Ludlow Massacre (4/20/1914), in which Colorado National Guards and private cops, hired by Rockefeller, attacked a tent colony of 1,200 miners and their families, killing 21, including women and children. The private cops were from the Baldwin-Felts Detective Agency, same ones involved in the Matewan Massacre in West Virginia. From September 1913 through end of May, 1914, up to 200 people had died in the Colorado Coalfield War, including 37 cops, soldiers and private detectives fighting for the coal companies, making it one of the deadliest strikes in U.S. history.