He had been living with Alzheimer's for years.
Fantasy author Terry Pratchett, creator of 'Discworld' series, dies at age 66
Discworld Series Author Sir Terry Pratchett Dies Aged 66
Beloved fantasy author Terry Pratchett dies at age 66
Discworld' Novelist Sir Terry Pratchett Dies at 66
Terry Pratchett - Wikipedia
Terry Pratchett, Discworld series author, dies aged 66, Terry Pratchett
Jim Henson Company adapting Terry Pratchett's 'Wee Free Men' as a film
Terry Pratchett quotes: Discworld author dies aged 66
Terry Pratchett, Author and Creator of Fantastical Worlds, Dies at 66