The loss of the flagship vessel of Russia’s Black Sea Fleet goes beyond wounded pride, robbing the military of important protection and capabilities as the war in Ukraine enters a crucial phase for Moscow.

How the Moskva caught fire late on Wednesday remains disputed. Russia’s defense ministry said the warship’s ammunition store detonated. The governor of Ukraine’s Odessa region, Maksym Marchenko, backed up by the defense ministry, said it was struck by two Neptune missiles, a new Ukrainian anti-ship system of which just one battery exists.

Russian news agencies reported late Thursday, citing the defense ministry, that the ship sank in rough weather while being towed back to port.