The submarine, which is of the Charley-I class (project 670A), lost its floating capacity due to a hole in its rusty hull, reports the Pacific Fleet press-centre. According to a Navy official in Moscow, the reactor of the submarine was defuelled, so the sub should not present any danger to the environment. The incident happened in the vicinity of the city of Petropavlovsk-Kamchatsky.

There are 11 submarines of Charley-I class stationed in the Pacific fleet. They are outfitted with one PWR type reactor and were constructed at Gorkiy shipyard from 1967 till 1972. Apparently all the submarines within this class are pulled out of service. On June 24, 1983, a submarine of this class, the K-429, sank at Kamchatka peninsula. It was later salvaged and towed to a navy yard. It sank again at quay on September 13, 1985. It was formally decommissioned in 1987.