During the Rolling Stones concert at the Altamont Speedway in California in 1969, a tragic incident occurred involving the Hells Angels motorcycle club. The Hells Angels were hired as security for the event, but due to various factors, including tensions among the crowd and excessive alcohol consumption, violence erupted. This resulted in the tragic death of concertgoer Meredith Hunter, overshadowing the event and marking the end of the optimistic and free-spirited 1960s.