The Chilean coup d’état of 1973 was a watershed event in the history of Chile and the Cold War. Historians and partisans alike have wrangled over its implications ever since. On September 11, 1973, less than three months after the first failed coup attempt, and less than a month after the Chamber of Deputies of Chile, where the Opposition held a majority, condemned Allende’s alleged breaches of the constitution and requested his forcible removal, the Chilean military overthrew president Salvador Allende, who died during the coup. General Augusto Pinochet exploited the situation to seize total power and establish an anti-communist military dictatorship which lasted until 1990.

The military rule was characterized by systematic suppression of all leftist opposition, which led some to speak of a "politicide" (or "political genocide"). The worst violence occurred in the first 3 months of the coup’s aftermath, with the number of suspected leftists killed or "disappeared" soon reaching into the thousands. In the days immediately following the coup, the National Stadium was used as a concentration camp holding 40,000 prisoners. Some of the most famous cases of "desaparecidos" are Charles Horman, a U.S. citizen who was killed during the coup itself, Chilean songwriter Víctor Jara, and the October 1973 Caravan of Death (Caravana de la Muerte) were at least 70 persons were killed.

Sources: Wikipedia
Coup
Dirty war