David W. Kosak passed away peacefully in the early morning hours of Tuesday, July 8, 2025 at home after a courageous battle with cancer surrounded by his loving family.  He was born on September 26, 1956, in Baraboo, WI, the son of Wilfrid and June (Rose) Kosak. 

He was an inquisitive and knowledgeable person who graduated from Reedsburg’s Webb High School in 1974.  In high school Dave was active in track and cross country and started the Ecology Club where one of the big projects he spearheaded was cleaning up the Baraboo River. He graduated top 10 in class before heading off to the University of Wisconsin Green Bay.  He was often on the Dean’s list before obtaining his bachelor’s degree from the University of Wisconsin Green Bay in Environmental Studies. 

 He married Katherine Jean Fitzgerald (Kathy) on May 31, 1986, in Reedsburg, WI, and together they had two beautiful children, Crystal (Kyle), Diederich-Kosak and Christopher. 

Dave, together with his brothers, Dan and Jim, operated Kosak Chimney Service for almost 50 years!  Together they built a successful community serving business known for integrity, incredible service and knowledge and they are still in business today!

Shortly after that, Dave along with his father and Kathy (his wife) started a business called Three’s Company, which featured their three businesses including custom jewelry design, antiques and chimney service.

In addition, Dave and his brothers started the Baraboo Bluff Brothers, hydroponic greenhouses that specialized in growing and selling the most beautiful produce. The Bluff Brothers were a weekly sight at the Madison Farmers market. He also had a huge vegetable garden at his home in Reedsburg.

Dave loved nature!  In particular, he enjoyed kayaking and canoeing and could figure out every possible way to tie a canoe to a vehicle! He also enjoyed hikes at local parks and wildlife areas with loved ones.  He was active in theater in Baraboo, sang in the church choir at Sacred Heart Catholic Church, Reedsburg, and was a member of the Reedsburg Area Toastmasters.  He loved journaling and being introspective. He was a prolific writer and thinker and often submitted many letters to the editor. He was not a person who conformed to society norms and was a champion of the underdog. He was a scrapper, resilient, hardworking, spiritual but not religious. 

  

Dave’s family would like to thank Agrace Hospice for their tender and caring support for the last few weeks of his illness.

He is survived by his wife Kathy, daughter, Crystal (Kyle) Diederich-Kosak and son, Christopher Kosak, brothers Dan Kosak (Patti), Jim Kosak, sisters Terri Knutson, Mary Seering (Jeff), Linda Kosak, Lori Kosak, Kathy Kosak, Barbara Kosak-Schlaefer.  In addition, to his in-laws Ed Fitzgerald (Gerry Ann), Dan Fitzgerald (Pat), Terri Radke (Pete), Peg Schluter (Jerry), Kristy Kasten Gary, Kelley BonDurant (Matt) and many nieces and nephews.

He was preceded in death by his brother John Kosak, his sister Jean Read, and his parents June (Rose) and Wilfrid Kosak.

Visitation for friends and family will be held at the Farber Funeral Home on Sunday, July 27, 2025, from 11:00 AM until 1:00 PM.  A celebration of life will NOT be held at the Fusch Center following the visitation.  It has been postponed.  A date and time will be announced.