Ukraine

Might be showing the tiny hole in the gas pipe that allowed in enough water to seize the engine? Just a guess. I don't know a lot about marine engines, even less about Russian designs, but water does not compress and can absolutely destroy an engine. The combustion chamber in a gas engine is where the mixing of air, fuel, and sometimes oil occurs. A piston rides inside that chamber under tight mechanical tolerances. If you allow water into the mix, and the piston attempts to compress that along with the fuel / air / sometimes oil, you get a situation where the water won't compress so something mechanical in the engine will. Can cause piston connecting rods to bend / break, can cause combustion chamber or sealing ring damage, can throw the engine out of time and cause issues on the valve train or crank shaft, sometimes even drive shafts. Would usually mean a full engine rebuild, and could mean an entire new engine block. Not an easy thing to fix.

Here's the description from Telegram.

The ship, which was based in the city of Baltiysk and was supposed to go on combat duty, suffered severe damage - due to the mysterious appearance of a hole in the gas pipe, water got into the engine: "Obukhov" choked.