What caused Doris Day to die?

As of Sept. 23, 2015, famed actress and singer Doris Day is still alive. She is perhaps best known as a song-and-dance actress in films such as "Calamity Jane" and "The Pajama Game."

Doris Day's real name is Doris May Ann Kappelhoff. Born in Cincinnati, Ohio, on April 3, 1922, Day was the youngest of three siblings. She began her career as a singer, and did not begin starring in films until 1948. Her film credits include "The Man Who Knew Too Much," "Please Don't Eat the Daisies," "Pillow Talk," "On Moonlight Bay" and "By the Light of the Silvery Moon." She also starred in the sitcom "The Doris Day Show" from 1968 to 1973.