McClure's 2nd Battalion—commanded by Lieutenant Colonel Ernest Peters—replaced the three battalions from the 132nd Regiment and prepared to assault the Gifu. Over the next four days, the Americans tried to feel out the Japanese positions with patrols. At the same time, the Gifu defenders attempted to wear down the Americans with night infiltration attacks. By 13 January, the 2nd Battalion had lost 57 killed or wounded. The battle casualties plus malaria reduced the battalion to 75% of its effective strength by the next day. To assist the battalion, the 35th Regiment's anti-tank gun company personnel were attached to the battalion as infantry. With the capture of the Sea Horse by the Americans, the Japanese in the Gifu were now isolated from the rest of the 17th Army. In a last message over his field phone before the line was cut, Inagaki refused an order from Oka to abandon his position and attempt to infiltrate back to friendly lines, instead vowing that his command would "fight to the last". Inagaki apparently refused the order because to do so would have meant leaving his sick and injured men behind. An American attack on the Gifu by the entire 2nd Battalion on 15 January was completely repulsed by the Japanese. In response, McClure relieved Peters of command on 16 January and replaced him with Major Stanley R. Larsen. Larsen decided to completely surround the Gifu and try to reduce it with a massive artillery bombardment on 17 January. In the meantime, the Americans used a loudspeaker to broadcast a surrender appeal in Japanese to the Gifu's defenders. Only five Japanese soldiers responded. One of the five reported that his company actually gathered to discuss the appeal, but decided not to surrender because they were too weak to carry their injured, non-ambulatory comrades with them to the American lines. Instead, they elected to perish together as a unit. One Japanese officer defending the Gifu wrote in his diary, "I heard the enemy talking in Japanese over a loud speaker. He is probably telling us to come out—what fools the enemy are. The Japanese Army will stick it out to the end. Position must be defended in all conditions with our lives." At 14:30 on 17 January, twelve 155 mm and thirty-seven 105 mm guns opened fire on the Gifu. Over the next one and a half hours, the American artillery fired 1,700 shells into