Remembering Altamont: Death of the Age of Aquarius : Rock music: It was 20 years ago today that outdoor festival organized by Rolling Stones turned into a nightmare with four people killed.

There are no plans to mark the anniversary of the rock concert at Altamont Speedway 20 years ago today--the day “free love” turned into fear and good vibes turned into violence.

Many of those who went are still trying to forget the Dec. 6, 1969, concert at a wind-swept, barren, sunbaked pasture 50 miles east of San Francisco.

The Rolling Stones organized the free “thank you” holiday concert for 300,000 fans, featuring the Jefferson Airplane, Santana, Crosby, Stills, Nash and Young and the Flying Burrito Brothers.

But the hastily organized event quickly deteriorated into a disaster that heralded the end of the rock festival phenomenon and shattered the dream of a utopian counterculture for the ‘60s generation.

The concert climaxed when a young black man drew a gun and was knifed to death near the stage by members of the Hells Angels, who had been hired as bodyguards to the Stones.

Another youth drowned in a canal and two more died after being run over by a car. Drug overdoses were rampant. Many of the fans ignored those who were in distress on “bad trips” so as not to miss the music.

Some people were injured during fights with the Hells Angels. Property damage to adjacent ranches was in the tens of thousands of dollars. The lack of planning resulted in what at the time was the area’s largest traffic jam.

Stones’ lead singer Mick Jagger surmised afterward: “If Jesus Christ had been there, he would have been crucified.”

Days after the festival, following Woodstock by barely six months, writer Todd Gitlin declared the concert “the end of the Age of Aquarius.”

The anarchy of the chilly December day was captured by filmmakers Albert and David Maysles in the documentary, “Gimme Shelter.”