William Carl Bollinger of Aurora, CO passed away at age 78 on July 7, 2023 of complications from kidney failure. 

   Bill was born in Aberdeen, South Dakota on October 3, 1944 to Janice and Charles Bollinger. Charlie Bollinger fought for the Marines at Iwo Jima during World War II. His experiences fascinated Bill and generated a life-long interest in World War II history and Iwo Jima and military aviation. 

   Bill had two older sisters, Pearl and Beulah, and a younger brother, Gerald. As a young boy Bill attended school near the homestead farm of his grandparents, Carl and Henrietta Sandquist, in Conde, South Dakota. His parents took Bill and Jerry and moved several times for a few years. Bill attended elementary schools in Texas, New Mexico and Colorado. He contracted polio at age 11 while living in Arlington, TX and spent 9 months in an iron lung.

In the late ‘50s Bill returned to South Dakota.He loved to hunt and help on the farm. In 1962 he graduated from Brentford High School. He attended South Dakota State University, Brookings from 1962-64. 

   Bill married Janis Nierman of Groton, South Dakota on July 12, 1964. They moved to Detroit, MI where he worked as a toolmaker. He earned his commercial pilot’s license and purchased his own Cessna airplane. He taught flying lessons and flew for Detroit Tigers pitcher Denny McLain.

   Bill graduated from Wayne State University in Detroit in 1968 with a B.S. degree in Mechanical and Industrial Engineering. 

  Bill and Jan’s daughter, Mandy Rae, was born in 1969. Bill and Jan moved to Denver in 1972. They divorced in 1974. Bill founded Sigma Design, Inc. in 1974. Sigma Design was one of the first companies to use computer technology - CAD - to design sprinkler systems. He sold the business in 1983.

   In 1986 Bill bought back the Fire Protection Division of Sigma Design, Inc. The new company was named Sigma Dynamics. 

   Bill sold part of Sigma in 1996, but retained part of the rights to the software. He renamed the company Sigma Solutions and enjoyed computer programming, writing newsletters and manuals and assisting clients until his death. 

In his free time, Bill loved to garden, engage in politics and watch movies on Turner Classic Movies. He spent time with his grandchildren visiting the Botanic Gardens, going to movies and museums and playing cards and board games. He attended First Universalist Church of Denver sporadically in the late ‘80s and almost every week from 2004-2014. 

   He is survived by his daughter, Mandi Everett, her children, daughter Nancy Grace Everett, 14, and son Aaron Jeremiah Everett, 10, and his sister Pearl Eldredge of Sioux Falls, SD. Services will take place Saturday, September 9 at 5 pm at First Universalist Church of Denver, 4101 E Hampden Ave., Denver, CO 80222. To view a longer obituary and leave memories for the family please visit 

https://www.dignitymemorial.com/obituaries/11364508