[1] Garns's colleagues at the Daggett architecture firm in Indianapolis recall the designer working on the game on one of the company's drawing boards.
George Wiley, a draftsman for the firm between 1957 and 1967, told Indianapolis Monthly: "We had two extra drawing boards and one day Howard was sitting over there.
Garns was alive when Number Place, renamed Su Doku, became popular in Japan in the mid-1980s, but died before it became an international phenomenon in November 2004, when it was printed by The Times of London.
He worked for his father's firm until the Second World War, when he became a captain in the US Army Corps of Engineers.
He died of cancer on October 6, 1989, and was buried in Crown Hill Cemetery, Indianapolis.