Karl William Koch III

Karl William Koch III, born on May 9, 1932, passed away on July 19, 2026, at the age of 94. A man of unwavering loyalty, deep Catholic faith, and extraordinary strength, Karl devoted his life to his family, his friends, his colleagues, and the steel erection industry he proudly served for decades.

Karl attended Manhattan College of Engineering and later served honorably in the United States Army during the Korean War. His service to his country was a point of quiet pride, reflecting his deep sense of duty and integrity.

Karl’s brilliant career began by joining his father in the family business, The Karl Koch Erecting Company, eventually becoming an owner and officer. The company delivered some of the county’s most iconic structures, becoming inextricably intertwined with our nation’s landmarks, built one by one and hidden in plain sight.

A devout Catholic, Karl lived his faith quietly but firmly, guided by a moral compass that never faltered. His loyalty to family and friends was absolute.

Karl was preceded in death by his beloved wife, Vivian Sullivan Koch, whom he cherished deeply. He is survived by his children: Vivian Mason (Jeffrey), Karl William Koch IV (Caroline), Cynthia Edwards, John David Mountain Koch, and Jill Ann D’Angelo (Joseph).

He was a proud grandfather to James Guy Mathews (Lauren), Emily Rose Repoli (Geoffrey), Brian Patrick Murray, Daniel Thomas Murray, Everett Karl Edwards, and Austin William Koch. His legacy continues through his great‑grandchildren, Jack Guy Mathews and Lily Rose Mathews, who will grow up hearing stories of the remarkable man whose name they carry forward.

Family will receive friends Monday, July 27, 2026, from 3:00 p.m. to 7:00 p.m. at Francis P. DeVine Funeral Home, 293 South Street, Oyster Bay, NY. Family and friends are invited to gather in remembrance and celebration of Karl’s life.

A Funeral Mass will be held on Tuesday, July 28, 2026, at 10:15 a.m. at St. Mary’s Church, 1300 Northern Boulevard, Manhasset, NY 11030, where Karl will be honored in accordance with his deep Catholic faith. Burial to follow Calverton National Cemetery.

In lieu of flowers donations may be made to Long Island State Veterans Home.

https://veteranshome.stonybrookmedicine.edu/donate

Karl’s life was one of devotion — to his faith, his work, his country, and most of all, his family. His strength, integrity, and love will remain with them always.