On October 21, 2008, Corporal O’Toole was manning the defensive tower of a combat outpost, in Afghanistan, when it was attacked by insurgents. As rounds impacted the tower and rocket-propelled grenades sailed over his head, Corporal O’Toole left the security of his location to fire an anti-armour weapon at the attackers’ location. After a successful hit, he remained in a highly vulnerable position, taking up a heavy machine gun to continue returning fire. Corporal O’Toole’s fearless and relentless actions suppressed the enemy, allowing friendly forces to quickly establish defensive positions and defeat the attack.