Operation Auca: Five U.S. missionaries are killed by the Waorani of Ecuador shortly after making first contact.

Operation Auca was an attempt by five Evangelical Christian missionaries from the United States to bring Christianity to the Waorani or Huaorani people of the rain forest of Ecuador. The Waorani, also known pejoratively as Aucas, were an isolated tribe known for their violence, against both their own people and outsiders who entered their territory. With the intention to evangelize the previously uncontacted Waorani, the missionaries began making regular flights over Waorani settlements in September 1955, dropping gifts, which were reciprocated. After several months of exchanging gifts, on January 3, 1956, the missionaries established a camp at "Palm Beach", a sandbar along the Curaray River, a few kilometers from Waorani settlements. Their efforts came to an end on January 8, 1956, when all five—Jim Elliot, Nate Saint, Ed McCully, Peter Fleming, and Roger Youderian—were attacked and speared by a group of Waorani warriors. The news of their deaths was broadcast around the world, and Life magazine covered the event with a photo essay.

A missionary is a member of a religious group who is sent into an area in order to promote its faith or provide services to people, such as education, literacy, social justice, health care, and economic development.

The Waorani, Waodani, or Huaorani, also known as the Waos, are an Indigenous people from the Amazonian Region of Ecuador who have marked differences from other ethnic groups from Ecuador. The alternate name Auca is a pejorative exonym used by the neighboring Quechua natives, and commonly adopted by Spanish-speakers as well. Auca means 'savage'.

Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contains the Galápagos Islands in the Pacific, about 1,000 kilometers (621 mi) west of the mainland. The country's capital is Quito and its largest city is Guayaquil.