On September 11th, 1973, the democratically elected government of Salvador Allende was ousted in a bloody coup by a military junta, led by Army General Augusto Pinochet.
As the military surrounded the presidential complex in Santiago, captured government workers were laid in front of tanks, and those remaining inside were told that if they did not surrender, the tanks would roll over their colleagues. Allende himself was found dead - according eye-witnesses he had been killed by machine-gun fire. According to the new regime, Allende had committed suicide.
The Pinochet regime went on, in partnership with other fascist South American governments and support of the CIA and US State Department under Henry Kissinger, to hunt down South American activists associated with leftist movements, in what became known as "Operation Condor."
(If you're interested in knowing more, the events of that day are presented in further detail in a documentary by the same name, subtitled "The Last Stand of Salvador Allende." It's a riveting and sometimes heartbreaking watch. The US State Department has also declassified a large volume of material which is now available online here, although large passages are redacted.)
The significance of what happened on September 11th, 2001 is not diminished by the fact that it shares a date with a massacre that happened in another country, exactly 28 years prior. It's historical significance lies in the fact that people from other countries were responsible for the deaths of thousands of people on American soil.
The reverse is usually the case.
