One of the World's Largest Floating Docks Takes Russian Aircraft Carrier, Sinks

Russia's military faces a major setback after its only aircraft carrier, key to its operations in Syria, was damaged when a crane crashed onto its deck.

The Admiral Kuznetsov was undergoing a refit at one of the world's biggest floating dry docks, known as the PD-50, which sank early on Tuesday morning. It sent a 70 tonne crane crashing onto the ship's deck, leaving a 16-foot gash, BBC reported.

One ship worker is missing and four others were injured and had to be treated for hyperthermia after falling into the freezing water, RIA Novosti reported.

The 305 meter (1,000 feet) long and 72 meter (236 feet) wide vessel was being overhauled in the Kola Bay near the northern Russian city of Murmansk, where the country's Baltic fleet is based.

The warship, launched in 1985 for the Soviet Navy, and which is due to return to service in 2021, was moved away before the dock sunk.

Aleksei Rakhmanov, head of the state-run United Shipbuilding Corporation, said "the vitally important parts of the aircraft carrier were not affected," Radio Free Europe reported.

Meanwhile, spokesperson for the ship repair dockyard, Evgeny Glayshev said that a detailed inspection of the hull was being carried out. "So far no problems have been identified. The incident will not affect the timing of the ship's repair," he told RIA Novosti.

It the latest setback for the carrier which played a key role in Russia's campaign in Syria, where Russian forces are supporting troops loyal to Bashar al-Assad.

In 2016, an MiG fighter jet crashed into the sea as it approached the ship, and an Su-33 crashed on landing when a cable broke, and the plane rolled off the deck.

In January 2017, the then British Defense Secretary, Michael Fallon dubbed it the "ship of shame" as it returned from its mission in Syria. The aging carrier was ridiculed by the British media as it sailed past the English Channel belching clouds of black smoke.