One of the largest floating dry docks in the world (PD-50) has sunk during the maintenance work on the Russian aircraft-carrying cruiser Admiral Kuznetsov. No casualties have been reported in the incident, which happened at a ship repair yard just outside of the northwestern port city of Murmansk. According to some reports, however, four employees fell into the water and had to be treated for hypothermia. According to the dockyard management, the PD-50 sank after its cisterns were overloaded with water due to a power outage. The PD-50 was one of the largest floating docks in the world, designed for the repair of large ships and submarines. The 330-meter-long and 76-meter-wide vessel was built in 1980 in Sweden for the Soviet Navy, and has a capacity of up to 80,000 tons. The Admiral Kuznetsov was not damaged in the incident, Sputnik reports. The aircraft-carrying cruiser is currently being towed to a nearby repair yard,where its maintenance will resume.