Donald Duncan Brennan, of Lancaster, PA died peacefully at Penn Medicine Lancaster General Hospital surrounded by his family on Thursday, January 9, 2025. Born on December 21, 1936 in Welland, Ontario. He was the son of the late Lloyd and Helen Brennan. He was the loving husband of Jacqueline "Jackie" (Magnan) Brennan whom he married in 1963.

Don received a Bachelor of Science in Mechanical Engineering (1961) and a Master of Business (1970) from McGill University. As an undergraduate, he served as President of the Mechanical Engineering School, President of his class, President of the McGill University Scarlet Key Honor Society and President of the Delta Upsilon Fraternity. Later, Don served on the boards of the Boys and Girls Club of Lancaster, the Lancaster Science Factory, and the Lancaster Country Club where he has been a member for almost fifty years. He was a member of The Moles and The Beavers, prestigious honorary national organizations for the heavy construction industry.

Don loved engineering. His professional life touched many people and aspects of society. As a Mechanical Engineer, he worked on countless civil and mechanical jobs tirelessly and enthusiastically, leading and mentoring professionals until his death. He began his career in 1960 at the Atlas Construction Company in Montreal, steadily rising to Assistant Chief Engineer building some of Canada's largest bridges, deep-sea marine wharfs and two sunken tube tunnels in Montreal and Mobile, Alabama.

In 1972, Don moved with his family to Pennsylvania and joined Elgood Mayo Corporation as Vice President and Chief Engineer, designing and supplying underground construction equipment for subways and deep-water tunnels throughout the U.S. In 1979, Don purchased the company and ran the business for the next 15 years engaged in over four thousand projects throughout the U.S. and Canada.

In 1994, Don sold Elgood Mayo to Gannett Fleming of Camp Hill, Pennsylvania and continued working as a consultant in the underground industry for many construction companies until he joined the Underground Division of Kiewit Infrastructure Company in 2011 as a Senior Design Engineer.

Don enjoyed playing golf, skiing, fishing, dancing, reading, playing gin with his buddies, and traveling. He loved life, adventures and had a great sense of humor.

Don is survived by his wife, Jackie, of over 61 years; his two sons, Douglas (Anabela) of Dalkey, Ireland and Derek (Beverly) of Atlanta; his daughter Michele Murphy (William) of Annapolis; and ten beautiful grandchildren: Jane, John, Simon, Matthew, Peter, Benjamin, Sam, Hailee, Hunter, and Kayla whom he loved dearly. He was preceded in death by two sisters, Marguerite Maudsley and Katherine Rockel.

The family would like to thank Dr. Matthew Brennan, Dr. Kathyrn Deprimo, Amy Shinkus, PA-C, and the extraordinary nurses on the eight floor of the Lancaster General Hospital who compassionately cared for him.

Friends and family are invited to Don's Mass of Christian Burial on Saturday January 25, 2025, at St. John Neumann Catholic Church 601 E. Delp Road, Lancaster, PA 17601 at 11:00 am with The Rev. Dan Powell as Celebrant. A visitation will be held at the church from 9:30am until the time of the service. A private interment will be held at St. Joseph's New Roman Catholic Cemetery.

In lieu of flowers, memorial contributions may be made in Don's memory to the Boys and Girls Club of Lancaster, 615 Fairview Avenue Lancaster, PA 17603 and the Lancaster Science Factory, 454 New Holland Avenue Lancaster, PA 17602.

Don's Funeral Service will be Live Streamed starting at 11AM. Please click on the St. John Neumann Church link below or visit their home page on their website at https://sjnlancaster.org/