That's going to leave a mark:
Russia has another naval disaster on its hands. Details have been slowly emerging, mainly because the submarine in question is a one-of-a-kind deep (6,000 meters) nuclear powered (AC-31 Losharik) vessel that can investigate items on the ocean floor. ...
The July 1st Losharik accident was caused by the lithium batteries overheating, causing a fire and then exploding. This killed fourteen of the 19 men abroad the submerged sub. The four surviving crew, and one civilian specialist, managed to surface the sub, shut down the nuclear reactor and get off onto the modified SSBN that serves as its mothership. Before the surviving crew left they were ordered to flood all compartments, to ensure that there was not another fire or explosion.
Russia may not be able to afford to repair the vessel.
And why did the sub go boom?
The sub was originally designed to use Ukrainian made silver zinc batteries but since 2014 Ukrainian military imports have been less “available” and Losharik switched to Russian made lithium batteries, which behave differently than silver zinc ones. Lithum batteries will catch fire and explode if they are short circuited.
So Ukraine, at war with Russia since early 2014 when Russia captured and annexed Crimea and then fought to take part of Ukraine's eastern Donbas region, sank a Russian sub in 2019.
Bask in the brilliance of Putin's "frozen conflicts!"