Western experts felt the explosions were due to the failure of one of the Kursk's hydrogen peroxide-fueled super cavitating 650mm torpedoes. They surmised that HTP, a form of concentrated hydrogen peroxide used as the propellant for the torpedo, was the culprit. Some of the HTP may have seeped through a rusted area in the torpedo casing thus causing the explosions. HTP was a cheap fuel and was used by the Russians as torpedo propellant as a cost-saving measure due to the lack of funds supporting the Russian Navy. In 1955, a British submarine was similarly lost when a torpedo using HTP exploded in the tube, sinking the submarine and killing 13 of its crew.
The Russians did not have the naval salvage equipment that could raise the sunken submarine and delayed hiring western companies that had such expertise and equipment. This need for western assistance exposed and embarrassed the Russian government on how limited their abilities were when faced with a disaster at sea like the Kursk. In 2001, two Dutch companies - Mammoet and Smit International - were contracted to raise the Kursk using the barge Giant 4. The barge was towed into place above the wreck but progress was slow due to regional storms. When the weather conditions improved, 26 steel cables were attached from the barge to the 18,000-ton vessel below and the Kursk wreckage was lifted off of the seabed floor. When it was raised to the surface, the submarine was attached to the bottom of Giant 4 for transport to a dry dock near Murmansk, Russia, to be examined for the cause of the sinking.
The Northern Fleet sent four tugs, a hydrographic vessel and, as escort, the cruiser Pyotr Veliky to bring the Giant 4 holding the Kursk back to the port complex at Murmansk. Once port had been made, the Russian Navy and salvage workers indicated the Kursk's reactors have been safely shut down and were not a danger. Work continued and the navies removed the remains of the sailors for burial and also removed the 22 Granit supersonic cruise missiles onboard. The bow was cut off before the body was lifted and, due to financial constraints, it was never raised and was destroyed by explosives in 2002.
The official investigation indicated the first blast detonated 5 to 7 torpedoes, causing a series of internal explosions that blasted a 200-foot hole forward that was measured on a geological seismometer as far away as Britain. The secondary explosions fatally damaged the Kursk. The Russian government denied claims that the sub's Granit cruise missiles were carrying nuclear warheads. Officially the report concluded that a faulty torpedo sank the Kursk. The remains of Kursk's reactor compartment were taken to Sayda Bay on Russia's northern Kola Peninsula. There the reactor compartments were defueled in early 2003 and the boat was dismantled.
After the first explosion, 23 crewmen made it to the aft 9th compartment - one of these crewmembers was Captain Lieutenant Dmitriy Kolesnikov. Recovery workers found notes on his body addressed to his wife talking about the men's final hours. The Russian military read the sorrowful personal notes in the media to the Russian nation. Worldwide sympathies and donations for the family's soon poured in.