867, a key terrain feature dominating the valley to the north, the North Koreans quickly shifted the 3rd Regiment, 6th Division, from Heartbreak Ridge to defend the hill. The North Korean deployment, however, did not help the embattled 23rd Regiment to capture Hill 931. Although the French Battalion replaced the 2nd Battalion and tried to advance south along the ridge line while the 1st Battalion sought to press north toward the crest of 931, the KPA 15th Regiment fought them off on 26 September. The 23rd's regimental tanks were able to move far enough north in the Sat'ae-ri Valley to send direct fire against some of the KPA bunkers covering the eastern approaches to Heartbreak, but could not destroy the heavy mortars and machine guns that halted the 2nd Division attack. After almost two weeks of futile pounding at the KPA defenses on Heartbreak, Colonel Adams told General Young on 26 September that it was "suicide" to continue adhering to the original plan. His own 23rd Regiment had already taken over 950 casualties and the division total for the period was over 1,670. As Colonel Lynch had the week before, Adams favored broadening the attack and dispersing the KPA's capacity to resist on Heartbreak. He felt that if the KPA forces in the vicinity of Heartbreak were engaged and unable to spare reinforcements or replacements for the KPA 15th Regiment, the 23rd could wear the regiment down and win the ridge. By 27 September Young and the Corps commander, General Byers, had come to agree with Adams and further assaults by the 23rd on Heartbreak were called off. Analyzing the initial attempts of 2nd Division to take Heartbreak, Young later characterized them as a "fiasco" because of the piecemeal commitment of units and the failure to organize fire support teams. The KPA mortars were especially effective, he pointed out, causing about 85 percent of the division's casualties up to this point. Renewed assault (4–15 October) Preliminaries In the new plan that the division operations officer, Maj. Thomas W. Mellon, prepared in late September, the earlier mistakes were to be avoided. All three regiments of the division would launch concentrated and co-ordinated attacks, supported by all the division's artillery, by a full-scale armored drive by the 72nd Tank Battalion up the Mundung-ni Valley, and by tank-infantry task force action in the Sat'ae-ri Valley. When the division issued the operation order on