Donald G. Killian, 91, passed away Thursday, March 19, 2020, of natural causes. Born Feb. 20, 1930, in Bernie, Missouri. He was the son of Otis Killian and Helen Pippins-Killian. His parents and his only sister preceded him in death. Don is survived by Marilyn Killian, his wife of 62 years, and his son Steve Killian of Seattle, Washington. Don was a graduate of Dexter, Missouri High School, Southeast Missouri State University at Cape Girardeau, the University of Missouri, and he completed additional graduate work at the University of Illinois at Urbana-Champaign. Don also served in the U.S. National Guard Army Reserve. Don and Marilyn married in June of 1958 in Ironton, Missouri. Shortly thereafter they moved to Wichita, Kansas where Don became a faculty member in the Mathematics Department at what was then called Wichita University. He taught regular term and often summer school as well. Don retired from WSU as an associate professor of mathematics in December 1994. He was known for his great sense of humor and kind disposition. Don was an avid reader of a broad range of topics including history, investments and finance, and mathematics. One of his favorite pastimes was watching sports, especially WSU Shocker basketball games. Due to pandemic-related delays and restrictions, a small Celebration of Life was held on Saturday, Oct. 30, 2021. Memorials in Don’s name have been established with WSU Foundation to support the Mathematics Department and University Congregational Church, 9209 East 29th Street North, Wichita KS 67226.