Peter Yarrow, one of three singers in the 1960s folk group Peter, Paul and Mary, has died. He was 86. Yarrow passed away on Tuesday, Jan. 7, after a four-year battle with bladder cancer, his publicist confirmed to The Guardian.

Peter Yarrow was a singer-songwriter and a social activist, but he was best known as one-third of the folk-music group Peter, Paul and Mary.

Peter Yarrow, one third of the chart-topping 1960s folk trio Peter, Paul and Mary - which helped popularize Bob Dylan as the voice of a generation - co-writer of the song “Puff, the Magic Dragon” and a prominent social activist,