 Moore disappeared in 1979, and although her remains were found in 1981, the cause and circumstances of her death are still unknown.Moore was born Marcia (pronounced mar-SEE-uh) Sheldon Moore, in Cambridge, Massachusetts on May 22, 1928, the only daughter of Robert L. Moore, founder of the Sheraton Hotel chain, and Eleanor Turner Moore, who was an artist, illustrator and esotericist.She had three brothers