In 1954 the first missionaries came to Amazon in Ecuador, the Capuchin missionaries in search for people living in the Amazon. Among them was Monsieur Alejandro Labaca. He also came to Ecuador; he worked at the coast and also in the Sierra (Andes). In 1964 he was one of the missionaries who searched contact with the Huaoranis.
The Mons. Labaca came to the Amazon in 1965 where he tried to civilize the Huaoranis, giving them salt, rubber boots, machetes, clothes. They tried to convert them into Catholics and thought them that walking around naked was very bad and sinful. Interested in these new things, the Huaoranis went along with them till certain extend.
After civilizing the Huaoranis, Labaca thought he could also do this with the Tagaeris. He went looking for them by plane and first threw down stuff like boots and machetes and later came in contact with them. He got overconfident about it and one of this trips he got killed by 40 spears, the way the Tagaeri use to kill and warn not to come back.
Of course the whole Catholic endeavor with their missionaries, was payed for by oil companies who desperately wanted to enter the rainforest. Shell was one of the first in this area, starting the town of Coca (Puerto Francisco de Orellana). They chose this spot for it, because right here had been a small Quichua settlement in the middle of pristine jungle.