Knowles, Wm. David, M.D. born May 11, 1938, in Tracy, MN, passed away at his home on May 17, 2015, after a one-year battle with pancreatic cancer. Public visitation Friday, May 29, 2015, 4-7 p.m. at Northview North Mankato Mortuary, 2060 Commerce Drive, North Mankato, MN. (507) 388-2288. Memorials preferred to the Mankato Salvation Army.