O'Donnell was last seen in Baltimore, Maryland on November 30, 1980. She was a resident of the Greenwich Village area in New York City, New York at the time, and her family lived in Oswego in upstate New York. They were all visiting Baltimore for Thanksgiving. O'Donnell's family dropped her off at the bus station for her ride to New York City, then traveled to Oswego by car. She was supposed to visit them for Christmas, but she never did. She has never been heard from again.

O'Donnell had initially traveled to New York City to become an actress or a singer, but she became involved in drugs and prostitution after her arrival and was occasionally homeless. She had hitchhiked occasionally since she was a teenager, and may have been sexually assaulted by someone who picked her up. Her family stated she had always kept in touch with them, however, and they don't believe she left of her own accord when she disappeared in 1980. Her case remains unsolved.