 She fought as a sniper in the 691st Rifle Regiment of the 383rd Rifle Division, Separate Coastal Army in battles for Kuban, Kerch, and Crimea.She died in the battle for Adzhimushkay, in which she killed 15 enemies after taking over the duties of the battalion commander, leading her battalion into the flight and remaining on the battlefield even after she was wounded in hand-to-hand combat.In a fight in the trenches a German soldier rushed at her but Kostyrina shot him first only to be killed by a stray enemy bullet.