That same afternoon , the North Koreans sent an American prisoner up the hill to Schmitt with the message , " You have one hour to surrender or be blown to pieces . " Failing in frontal infantry attack to reduce the little defending force , the North Koreans now meant to take it under mortar fire . Only 45 minutes later North Korean antitank fire came in on the knob and two machine guns from positions northward and higher on the slope of Hill 209 swept the perimeter . Soon , mortars emplaced on a neighboring high finger ridge eastward registered on Schmitt 's perimeter and continued firing until dark . The machine gun fire forced every man to stay in his foxhole . The lifting of the mortar fire after dark was the signal for renewed North Korean infantry attacks , all of which were repulsed . But the number of killed and wounded within the perimeter was growing , and supplies were diminishing . There were no medical supplies except those carried by one aid man .