At the same time that Rio Tinto is becoming the biggest copper producer, protests increase, which culminated in “the year of the shots.” A peaceful demonstration of miners, farmers and other workers demanding better working conditions and a reduction of the polluting copper fumes ends up in a massacre where it is estimated over two hundred people are killed.

García-Gómez, J. and Pérez-Cebada, J., 2020. A Socio-Environmental History of a Copper Mining Company: Rio-Tinto Company Limited (1874–1930). Sustainability, 12(11), p.4521-4538.