Ríos returned to Puerto Rico in 1990, retiring in the town of Fajardo. In 1999, she was diagnosed with lung cancer and she left the island to return to the mainland. She was hospitalized in Sarasota, Florida. Marie Teresa Rios died on October 17, 1999 and her funeral was held at the Ft. Myer Old Post Chapel. Representatives of the Special Operations Command from Fort Bragg were present. Her ashes were buried with her husband at Arlington National Cemetery on November 12, 1999. She was survived by her four children Dr. Stephen, Richard (former coach of the Indiana Pacers), Michael and Trilby Versace.