 The large-scale colonization of Rondônia happened only in the second half of the 20th century.At this time many people died from the introduction of preventable diseases to which they were not immune, and as a result, in the 1950s the Tuparí people were nearly wiped out entirely by measles.According to Caspar (1956), there were only 67 survivors of these epidemics, who were then forced to work for slave wages.