As Mitchell and A Company was on patrol south of Yudam-ni the next day, Mitchell's platoon which was on point, got hit hard by a Chinese ambush near the small village of Hagsang-ni which caused a fierce firefight with the Chinese and many casualties on his platoon. Lt. Mitchell immediately took action at the front of his platoon and shown "great personal valor and extraordinary heroism". Despite being wounded, he personally sacrificed his own life to save the lives of the Marines which were wounded in his platoon, and the other outnumbered Marines in his platoon when they were being withdrawn. For his leadership and heroic actions during the enemy's attack and counterattack on his platoon that included hand-to-hand fighting, he was awarded the Medal of Honor (posthumous). He was listed as missing in action and his remains were not recovered.The Battle of Chosin Reservoir would begin on the night of November 27, when both the 7th Marines and 5th Marines were counter-attacked by a massive number of Chinese troops which would soon force the surrounded 1st Marine Division at Yudam-ni to begin their withdrawal from North Korea.