 On 16 July 1949 , Arana delivered an ultimatum to Arévalo , demanding the expulsion of all of Árbenz ' supporters from the cabinet and the military ; he threatened a coup if his demands were not met . Arévalo informed Árbenz and other progressive leaders of the ultimatum , who all agreed that Arana should be exiled . Two days later , Arévalo and Arana had another meeting ; on the way back , Arana 's convoy was intercepted by a small force led by Árbenz . A shootout ensued , killing three men , including Arana . Arana 's supporters in the military rose up in revolt , but they were leaderless , and by the next day the rebels asked for negotiations . The coup attempt left approximately 150 dead and 200 wounded . Many of Arana 's supporters , including Carlos Castillo Armas , were exiled . The details of the incident were not made public . 
