He was born in Manchester on September 14, 1930, the son of Henri and Angelina (Savoie) Gagnon. He was educated in the local school system.
During the Korean War, he served in the US Army.
Prior to retirement in 1989, he had been employed in the accounting department at Bank of New Hampshire (now TD Bank) for 35 years.
He was a member of the Knights of Columbus #5260, DAV Chapter 1, the CWV Post 1749, the American Legion Henry J. Sweeney Post #2 as well as the League of 1000 Men of the Monastery of the Precious Blood.
Bertrand enjoyed playing cards, spending time at the West Side Senior Center, and had also volunteered much of his time at the Catholic Medical Center.
Family members include his wife of 46 years, Pauline T. (Plourde) Gagnon of Manchester; two daughters, Anne Gagnon of Manchester, Lucie Poulicakos and her husband Daniel of San Carlos, CA; four grandchildren, Sarah Lynn, Alicia, Jacob, and Zoey; one sister, Pauline Cote and her husband Arnold of Manchester; many nephews, nieces and cousins. He was predeceased by his brothers Real, Raoul, and Marcel and his sisters Juliette Beliveau, Lucille Soucy, and Rachel Gagnon.
A Mass of Christian burial was celebrated on Tuesday, January 3, 2012 in Blessed Sacrament Church. Burial followed in Mt. Calvary Cemetery, 474 Goffstown Road.
Memorial donations may be made in his memory to the Blessed Sacrament Food Pantry, 14 Elm St, Manchester, NH 03103.