7th Marines were to proceed north of Hamhung to relieve a South Korean Army unit which had fought with Chinese Communist forces (two hundred thousand Chinese troops had entered North Korea on October 19 by secretly crossing the Yalu River, and launched an offensive on October 25). On November 2, the 7th Marines reached the South Koreans with little opposition (November 1 was the first confrontation between the Chinese and the U.S. military). However, Chinese presence increased after this. On November 3, as Company A was in a defensive position near Hamhung, Mitchell's platoon was hit hard suddenly by the Chinese and almost overrun. Mitchell "rallied his men to repel the attack and he, although painfully wounded in the ensuing action, refused to be evacuated until the danger of a serious break-through was averted." He was awarded the Silver Star (posthumous). On November 4, one of Mitchell's platoon's squad leaders, Sergeant James Poynter, during a bayonet attack against the Chinese, took out three enemy machine guns with grenades, thereby saving his squad and platoon during a hill fight (Hill 532) at Sudong, and was posthumously awarded the Medal of Honor. On November 15, the 7th Marines and the 1st Marine Division completed their move north to Hagaru-ri, at the southern tip of the reservoir. The division was to proceed more north to Yudamni, on the western side of the Chosin Reservoir and to seize it, which was done with little resistance on November 25. 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of the Marines which were wounded in his platoon, and the other outnumbered Marines in his platoon when they were being withdrawn.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