Ask most Americans about terrorist attacks committed by foreigners on US soil and there’s more than a good chance they’ll point to the September 11, 2001 bombings of the World Trade Center, or the 2013 Boston Marathon bombing. At a push, they might even point to the bombing of Pearl Harbor, which, while not a case of terrorism, was until September 11 the worst foreign attack on US soil in the country’s history.

Few are likely to talk about the time an ostensibly friendly government — one partially installed by the United States in an act of covert regime change, no less — murdered one of its own dissidents in a car bombing in the heart of the nation’s capital, killing a US citizen in the process. Yet forty years ago today, that’s precisely what happened when Orlando Letelier, a former Chilean diplomat and outspoken critic of the Pinochet dictatorship which had come to rule the country, and his two coworkers prepared to travel to work.

On a rainy fall morning on September 21, 1976, as Letelier’s car traveled down the block of 2300 Massachusetts Avenue, just past Sheridan Circle and along Washington, DC’s Embassy Row, a plastic explosive attached to the underside of the vehicle detonated, killing Letelier and one of his occupants, twenty-five-year-old Ronni Moffitt. Passers-by watched as the flaming wreck crashed into a nearby Volkswagen, and Michael Moffit, Ronni’s husband, crawled out of the back. They had been married only 113 days.