Walt Disney

Context: Disney had been a heavy smoker since World War I. He did not use cigarettes with filters, and had smoked a pipe as a young man. In November 1966, he was diagnosed with lung cancer and was treated with cobalt therapy. On November 30 he felt unwell and was taken to St. Joseph Hospital where, on December 15, ten days after his 65th birthday, he died of circulatory collapse caused by lung cancer. Disney's remains were cremated two days later, and his ashes interred at the Forest Lawn Memorial Park in Glendale, California.  His estate included a 14 percent holding in Walt Disney Productions worth $20 million. He left 45 percent of his estate to his wife and children--much in a family trust--and 10 percent to his sister, nieces and nephews. The remaining 45 percent went into a charitable trust, 95 percent of which was designated for CalArts, to build a new campus (a figure of around $15 million); he also donated 38 acres (0.154 km2) of the Golden Oaks ranch in Valencia for construction of that school. The university moved there in November 1971.  The release of The Jungle Book and The Happiest Millionaire in 1967 raised the total number of feature films that Disney had been involved in to 81. When Winnie the Pooh and the Blustery Day was released in 1968, it earned Disney an Academy Award in the Short Subject (Cartoon) category, awarded posthumously. After Disney's death, his studios continued to produce live-action films prolifically but largely abandoned animation until the late 1980s, after which there was what The New York Times describes as the "Disney Renaissance" that began with The Little Mermaid (1989). Disney's companies continue to produce successful film, television and stage entertainment.  Disney's plans for the futuristic city of EPCOT did not come to fruition. After Disney's death, his brother Roy deferred his retirement to take full control of the Disney companies. He changed the focus of the project from a town to an attraction. At the inauguration in 1971, Roy dedicated Walt Disney World to his brother. Walt Disney World expanded with the opening of Epcot Center in 1982; Walt Disney's vision of a functional city was replaced by a park more akin to a permanent world's fair. In 2009, the Walt Disney Family Museum, designed by Disney's daughter Diane and her son Walter E. D. Miller, opened in the Presidio of San Francisco. Thousands of artifacts from Disney's life and career are on display, including numerous awards that he received. In 2014, the Disney theme parks around the world hosted approximately 134 million visitors.  Disney has been portrayed numerous times in fictional works. H. G. Wells references Disney in his 1938 novel The Holy Terror, in which World Dictator Rud fears that Donald Duck is meant to lampoon the dictator. Disney was portrayed by Len Cariou in the 1995 made-for-TV film A Dream Is a Wish Your Heart Makes: The Annette Funicello Story, and by Tom Hanks in the 2013 film Saving Mr. Banks. In 2001, the German author Peter Stephan Jungk published Der Konig von Amerika (trans: The King of America), a fictional work of Disney's later years that re-imagines him as a power-hungry racist. The composer Philip Glass later adapted the book into the opera The Perfect American (2013). CANNOTANSWER

Question: When did Walt Disney become ill?
Answer: In November 1966, he was diagnosed with lung cancer and was treated with cobalt therapy.