 On the morning of November 30 , the 9th Infantry Regiment led the withdrawal by attacking the roadblock . Four tanks were first sent down the road and the Chinese held their fire . Encouraged by this development , Colonel Sloane ordered the 9th Infantry Regiment to press forward , but Chinese machine gun and mortar fire immediately stopped the advance at 9 a.m. The ROK 3rd Infantry Regiment attached to the 2nd Infantry Division was sent to reinforce the US 9th Infantry Regiment , but it was routed by friendly fire . With no contacts between the American commands and the British units , the Middlesex Regiment advanced to the south end of the valley without attacking the roadblock . Believing that the roadblock was short and the British were attacking up the road , Keiser ordered the 2nd Infantry Division to run through the blockade at 10 a.m. 
