David A. Tyler

Born on August 11, 1934, in Peoria, IL, to Jay and Mary Ellen (Cassidy) Tyler, he was the eldest of five children: Nancy, John, Jay and Michael. David built a life grounded in quiet strength, integrity, and devotion. Upon graduation from high school, David enlisted in the United States Marine Corp where he served for 3 years; he was proud to be a Marine and would often say, “Once a Marine, always a Marine.” On November 29,1958, he married the love of his life, Mary Kathryn (Bour) Tyler (she survives), and together they created a family that became his greatest source of pride and joy. While working his way through college at Bradley University, he excelled in the field of engineering—his determination and brilliance evident even then.

David began his career at McDonnell Douglas in Missouri working on the Gemini and Apollo projects helping design the guidance systems, but in 1964 returned to Illinois to begin his long and impactful tenure with Caterpillar Inc., Peoria, IL. His colleagues would remember him as a trailblazer in Research and Reliability—an engineer whose intellect was matched only by his humility. He was a teacher, mentor, and trusted guide to many, leaving behind a legacy of innovation, curiosity, and quiet leadership.

To his family, David was so much more than his accomplishments. He was gentle, steady, and deeply devoted— a husband of nearly 68 years, a loving father to five children: Suzanne (Tyler)& Ray Tealbey, Michelle Tyler, Steven & Kristine (Tunney) Tyler, Brian & Karen (Harmon) Tyler, and Kristine (Tyler) & Charlie Rose, a proud grandfather to 11 grandchildren, and a delighted great‑grandfather to 5 little ones who always made his eyes light up.

Though soft-spoken, David had a dry wit that could catch you by surprise and a compassionate heart that compelled him to care for every stray cat that wandered his way. He loved watching and feeding his backyard birds, finding peace in their company. His fascination with WWII history was unmatched, and he happily shared his knowledge with anyone who wished to learn. Beneath his quiet nature was a man of deep loyalty, wisdom, humor, and love—qualities that shaped the lives of all who knew him.

A celebration of David’s life will be held later. In lieu of flowers, the family welcomes donations to the Dream Center or Sophie’s Kitchen, both in Peoria, IL, in his honor. If you are not able, the next time you feed the birds, think of him.

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