Connie Francis, a pop star of the late 1950s and early 1960s known for hits such as 'Who's Sorry Now,' has died at 87 due to undisclosed causes.

1950s singer Connie Francis, whose hits included “Pretty Little Baby,” “Stupid Cupid” and “Who’s Sorry Now?,” has died at 87, her publicist and friend, Ron Roberts, announced to fans through a Facebook post.

From 1958 to 1964, she was the most popular female singer in the United States, selling 40 million records with tunes like “Who’s Sorry Now” and “Where the Boys Are.”