August 12, 2000
The nuclear-powered submarine Kursk sinks in the Barents Sea due to an explosion in its torpedo room, killing all the 118 submariners on board.
August 30, 2003
Nine crew members die when the K-159 nuclear submarine sinks in the Barents Sea during a storm. The K-159 was being towed to a harbor to have its nuclear reactors stripped when a storm broke.
https://www.rferl.org/amp/major-russian-submarine-accidents-since-2000/30033592.html
Not to worry, the Russians have a whole fleet of submarine tug boats located under the Black Sea. New tugs coming online every month.