К-3 was a project 627 "Кит" (kit, meaning "whale"; NATO reporting name "") submarine of the Soviet Navy's Northern Fleet, the first nuclear submarine of the Soviet Union. The vessel was prototyped in wood, with each of five segments scattered between five different locations about Leningrad, including the Astoria Hotel. She was built in Molotovsk, launched on 9 August 1957, commissioned in July 1958, and homeported at Zapadnaya Litsa on the Kola Peninsula. K-3 was designed by Vladimir Peregoudov. Her initial captain was Leonid Osipenko, and the executive officer was Lev Zhiltsov, who had the important task of assembling the first crew. Arctic voyage On 17 June 1962, by this time under the command of Zhiltsov, К-3 reached the North Pole underwater, the first among Soviet submarines (a feat performed nearly four years earlier by ). The submarine also surfaced on the Pole (a feat performed three years before by ). For this voyage, she was awarded the name Leninsky Komsomol (Ленинский Комсомол) on 9 October 1962, and her crew, rather than training in military operations, began taking part in many congresses and conferences. This idle life continued until Summer 1967 when a boat that had been scheduled for patrol in the Mediterranean Sea was unavailable. Leninsky Komsomol was tasked with that patrol. She was assigned a new commander, Captain Second Rank Stepanov, and her executive officer arrived aboard only two hours before she put to sea. Whatever the initial material condition of the boat, the crew was not ready for sea. By the time they reached the Mediterranean, the air regeneration system had failed and the temperature on board was . Once in the Mediterranean, Leninsky Komsomol was given the mission of following an American ballistic missile submarine. 1967 accident On 8 September 1967, while transiting the Norwegian Sea, a fire broke out in the submarine's hydraulic system, and crew members in the compartment when the fire broke out had to evacuate the compartment. The flames spread to other parts of the submarine. The automatic extinguishers were based on carbon dioxide gas, which killed the crew members who were in the first and second compartments in the submarine. When the dividing door in the bulkhead from the third compartment was opened to see what had happened to the people in the second compartment, the gas spread, and more people lost consciousness. The forward compartments were then completely sealed off,