During World War II, Berra served in the United States Navy as a gunner's mate on the attack transport during the Normandy landings. A Second Class Seaman, Berra was one of a six-man crew on a Navy rocket boat, firing machine guns and launching rockets at the German defenses on Omaha Beach. He was fired upon, but was not hit, and later received several commendations for his bravery. During an interview on the 65th Anniversary of D-Day, Berra confirmed that he was sent to Utah Beach during the D-Day invasion as well.