On 28 August 2003, "K-159" and her pontoons were manned by ten Russian sailors and taken under tow to Polyarny. That crew kept the pontoons pressurized and the submarine hull pumped out, but during the early morning hours of 30 August they encountered a squall that ripped away one of the pontoons. "K-159" did not sink immediately, but was clearly in distress. Northern Fleet was notified at 01:20, and Admiral Suchkov arrived at headquarters 20 minutes later. By 03:00 the wreck had sunk in the Barents Sea, 200 meters down, with nine of her crew and most likely 800 kilograms of spent nuclear fuel containing some 5.3 gigabecquerels of radionuclides.