Robert John Ladner

Robert John Ladner, 89, of Lakeway, Texas—formerly of Chandler, Arizona; Fort Myers, Florida; and Chicago, Illinois—passed away peacefully on October 2, 2025, surrounded by his loving family. He was an inspiration to all who knew him, a shining example of a life well lived. His kindness, generosity, and humor will be deeply missed.

Born on September 25, 1936, to Bernard and Bernice (Nicholas) Ladner, Robert married Patricia Coakley in 1959. Patricia preceded him in death on November 14, 2023.

Together, they shared 64 wonderful years and proudly raised five children: Patsy Ladner (our angel in heaven), Bob Ladner (Donna), Renee McDonough (Ed), Margie Lanthier (Kurt), and Kathleen Ladner. Robert was a devoted grandfather to 13 grandchildren and 9 great-grandchildren—with a tenth on the way—all of whom he cherished deeply. One of his greatest joys was his large, close-knit family.

He is also survived by his brother, Dick Ladner, with whom he shared a lifelong bond of friendship and mutual respect.

Robert earned a Bachelor of Science degree in Mechanical Engineering from Purdue University. After early roles at Visking Corp (a division of Union Carbide) and Perkins and Will, he co-founded Environmental Systems Design, Inc. in 1967. Based in Chicago, the firm became a leading mechanical consulting engineering company specializing in HVAC, electrical, plumbing, and fire protection design for high-rise commercial, residential, healthcare, and educational facilities.

An avid boater, Robert found peace and joy on the water. His passion for boating led him to serve as Commodore of the Gulf Harbour Yacht Club in Fort Myers, Florida—a role he embraced with pride and enthusiasm.

In his later years, Robert also discovered a love for performing in church shows and singing in the choir, embracing the arts with the same passion he brought to engineering and family life.

Relatives and friends are invited to attend a visitation at 9:00 a.m., and funeral Mass at 10:00 a.m. at Old St. Patrick’s Catholic Church in Chicago on November 14, 2025. Interment will follow at Assumption Catholic Cemetery in Glenwood.