• Judy Garland (Dorothy Gale): Died on June 22, 1969, from an accidental barbiturate overdose at age 47. https://www.biography.com/actor/judy-garland
• Frank Morgan (The Wizard): Died on September 18, 1949, from a heart attack at age 59. https://www.imdb.com/name/nm0601268/bio
• Ray Bolger (The Scarecrow): Died on January 15, 1987, from bladder cancer at age 83. https://www.biography.com/actor/ray-bolger
• Bert Lahr (The Cowardly Lion): Died on December 4, 1967, from pneumonia at age 72. https://www.imdb.com/name/nm0487985/bio
• Jack Haley (The Tin Man): Died on June 6, 1979, from a heart attack at age 81. https://www.biography.com/actor/jack-haley
• Billie Burke (Glinda): Died on May 14, 1970, from natural causes at age 85. https://www.imdb.com/name/nm0000011/bio
• Margaret Hamilton (The Wicked Witch): Died on May 16, 1985, from a heart attack at age 82. https://www.biography.com/actor/margaret-hamilton
• Charley Grapewin (Uncle Henry): Died on February 2, 1956, of natural causes at age 86. https://www.imdb.com/name/nm0332128/bio
• Victor Fleming (Director): Died on January 6, 1949, from a heart attack at age 59. https://www.biography.com/filmmaker/victor-fleming

Looks like only the scarecrow died from it (and his cancer may not have even been caused by the asbestos)