1969 was a huge year in the history of the U.S., as the free-love hippie movement soured and turned bad. Sunday marks the 40th anniversary of the the concert at Altamont Speedway in Costra Costa County (map) where the Rolling Stones hired the Hells Angels to protect the stage and they wound up killing some poor bastard as cameras rolled for the film that would become Gimme Shelter.

Wikipedia has some interesting background on the incident, and Rolling Stone has a nearly contemporaneous report, including a detailed narration of what the film shows of the killing. An Oakland Tribune story reminds us that the biker who stabbed the concert-goer was acquitted by a jury, which ruled he acted in self defense.