Bernard Charles Denomy DSO was born in Chatham, Ontario. In May 1941, he enlisted in the RCAF in Port Arthur, Ontario (now part of Thunder Bay). Prior to enlistment he was living in Temiskaming, Québec. Denomy received air crew instruction at RCAF training schools in Canada and graduated from No. 11 Service Flying Training School in Yorkton, Saskatchewan in April 1942.

Overseas, he was eventually assigned to No. 162 Squadron RCAF, whose role at one time was to search for and attack enemy U-boats using the northern route from Germany to reach the North Atlantic and sink Allied ship convoys. In June 1944, the squadron was based in the Shetland Islands, Scotland. On June 24, 1944, Denomy was a member of the crew of Squadron Leader David Ernest Hornell, who was pilot and captain of a Catalina Canso amphibian, when a German submarine was sighted, and their Canso was about 1,000 miles from home base in the Shetland Islands, Scotland.

The sub was surfaced and traveling at high speed. Hornell and his crew immediately swung into attack position but not before the U-boat's flak had torn big holes in his wing and the starboard engine caught fire. Despite being caught in withering enemy fire, Hornell and his crew moved the Canso into position for the crew to sink the sub, which they did. The burning engine dropped off and by superhuman effort Hornell brought the plane safely down to the raging sea. With only one serviceable dinghy the crew of 8 took turns going into the freezing water to hang by the side.

After 21 hours in the icy sea, two flight engineers had died, and Hornell lost consciousness. They were picked up by a rescue launch and Hornell died shortly after. Hornell was awarded the Victoria Cross for his skill and valour in facing painful death. Other members of the crew were decorated for their bravery and hardships suffered as the result of their attack to sink the U-boat. Flight Lieutenant Denomy was awarded the Distinguished Service Order (DSO) for his part in the sinking of the sub and the assistance provided to other crew members during the 21 hour ordeal in the stormy and freezing waters of the North Sea.