USS O-5, a 521-ton O-1 class submarine, was built at Quincy, Massachusetts. Commissioned in June 1918, she operated along the Atlantic coast for the next four months, and was en route to European waters when the First World War ended in November 1918. Thereafter, O-5 was assigned to the New London Submarine Base, Connecticut. She was classified as SS-66 in 1920, and her base was changed to Coco Solo, Panama Canal Zone, in 1923. On 28 October of that year, while in Limon Bay, Panama, the submarine collided with the steamship Abangarez and quickly sank. Three of her crew were lost in this tragic accident, and two others spent many hours on board the sunken O-5 until they could be rescued. For his "heroism and devotion to duty" in assisting a shipmate in the sinking submarine, Torpedoman 2nd Class Henry Breault received the Medal of Honor. O-5 was raised soon after her loss, but she was too badly damaged to be worth repairing and was sold for scrapping in December 1924.