Soviet submarine B-37
A Soviet submarine B-37 exploded on January 11, 1962 after a sudden fire in the torpedo chamber.
At the time of the accident, the ship was anchored at the base of the Northern Fleet (Polyarny City).
The explosion caused a complete destruction of submarine B-37 and the next submarine S-350.
122 identified individuals were killed, including submarines, several other ships and shipyard workers.
Atomic submarine Kursk
On 12 August 2000, the Russian nuclear submarine Kursk crashed during a fleet exercise of the northern fleet on the Barents Sea.  The test results showed that the hydrogen peroxide torpedo of a ship had failed and caused a devastating explosion.
All 118 members of the Kursk crew were killed.
] This tragedy sparked a wave of criticism against the Russian government and navy, making it difficult for Putin to meet in the first term of the presidency.
Soviet submarine K-129
The diesel-powered submarine K-129 of the Pacific Fleet suffered on 8 March 1968 about 2890 km to the west. North Hawaii.
Previously, the K-129 from the end of February had contacted the command post. The authorities said that the ship may have fallen due to flooding after lowering the depth across the border.
Other causes included the explosion of hydrogen batteries, the collision with the USS Swordfish or the explosion of rockets.
Despite many attempts, the Russian navy still can not locate the body. Ship K-129.
In 1974, the US began searching for wrecks, and a small part of the ship was found. However, the exact location of the K-129 is still kept secret by US intelligence.
Soviet submarine S-80
The Soviet Union's S-80 diesel-electric submarine sank on January 27, 1961, on the Barents Sea, after being lowered in depth.
Earlier, the S-80 should have shut down the icebreaker system, preventing the valve from allowing water to flow into the jammed ship.
Water overflowed, causing the ship's engine to stop working. And the ship quickly sank to the bottom of the sea, killing all 68 sailors.
Soviet submarine K8
The accident occurred on April 12, 1970 off the coast of northern Spain after the electric shock had caused a fire in two submarines
At the time of the accident, the K8 involved in a large-scale maritime activity.
Strong winds and rough seas caused ships to sink before they were brought to safety.
52 sailors were killed by CO2 poisoning and suffocation. 73 other lucky survivors were immediately brought to the rescue ship.
This was the first loss with Soviet nuclear submarines.