Thomas D O’Brien Sr. (Obie) (Grandpa)age 100 passed away on November 24, 2025 at Catholic Medical Center in Manchester, NH surrounded by his family. He was born on July 2, 1925 in Springfield, MA, son of the Late, George, C. O’Brien and Melanie (Verdun) O’Brien. Thomas honorably served in the US Navy during WWll. Upon returning from duty, he worked as a machinist at Savage Arms and later as a Chicopee Fire fighter for 28 years, proudly advancing to lieutenant status before retiring. Obie had a strong bond with his fellow firefighters especially his dear friend William da Cunha. Tom then worked as a custodian at St. Patrick school in Chicopee enriching many lives with his faith, friendliness, and love of children. Obie was the loving father of 5 children and was often seen playing kickball or wiffel ball with them and their friends. He, along with his wife Jane volunteered in various capacities throughout their retirement. He was a third-degree member of the Knights of Columbus Elder council # 69 in Chicopee, MA. After moving to New Hampshire, he then became a 4th degree member at council # 3035 in Milford, New Hampshire. Tom loved music! He was always singing and had a beautiful voice. He was a member of the church choir at Saint Patrick’s in Chicopee for several years. He is pre-deceased by his wife of 54 years Jane A.(Michon) O’Brien who passed away in 2007, his son Thomas O’Brien Jr. who passed away in 2012, his brother James who passed away in 1988 and and great grandson Austin who passed away in 2003. He is survived by his son, Michael O’Brien, and his wife Caren of Mason, NH, three daughters, Elizabeth (Beth) Stebbins and her husband Dennis of Chicopee, Mary Prouty and her husband, Robert of Chicopee and Veronica Uzar and her husband Ralph of Amherst, NH. 10 grandchildren, 12 great grandchildren, and many loving nieces and nephews. Grandpa’s kindness, faith, benevolence, and love will be missed by family and friends. Calling hours will be held on Monday, Dec. 8, 2025 from 4:00 - 7:00 PM at the Grise Funeral Home, 280 Springfield St, Chicopee. A funeral service will be held on Tuesday, Dec. 9, 2025 from 9:30 - 10:30 AM at the funeral home followed by a Mass of Christian burial in St Rose de Lima Church at 11:00 AM. Burial will take place in St Patricks cemetery. In lieu of flowers please make donations to Shriners hospital, St. Jude children’s, or St Labree Indian school.