area around Chondong-ni. However, Eighth Army requested several of its units to redeploy to Taegu to be used elsewhere on the front, particularly at the Naktong Bulge An attempt to move the 25th Infantry Division's division trains through the valley became mired in the mud through the night of August 10–11 and was attacked in the morning by KPA who had driven American forces from the high ground. In the confusion, KPA armor was able to penetrate roadblocks and assault the supporting artillery positions. The surprise attack was successful in wiping out most of the 555th and 90th Field Artillery Battalions, with much of their equipment. Both KPA and US armor swarmed to the scene and US Marine aviation continued to provide air cover, but neither side was able to make appreciable gains despite inflicting heavy casualties on one another. US forces were unsuccessful in retaking the positions where the artillery was overrun, suffering numerous casualties in several failed attempts to do so. Upon later inspection, the bodies of 75 men, 55 from the 555th Field Artillery and 20 from the 90th Field Artillery, were found executed when the area again came under American control, in what was later known as the Bloody Gulch massacre. Task Force Kean was forced to withdraw back to Masan, unable to hold its gains, and by August 14 it was approximately in the same positions it had been in when it started the offensive.Task Force Kean had failed in its objective of diverting North Korean troops from the north, and also failed in its objective of reaching the Chinju Pass. However, the offensive is noted to have significantly increased morale among the troops of the 25th Infantry Division, which performed extremely well in subsequent engagements. The KPA 6th Division had been reduced to 3,000–4,000 and had to replenish its ranks with South Korean conscripts from Andong. Fighting in the region continued for the rest of the month. UN redraws battle lines Walker then ordered the US 25th Infantry Division, under Kean, to take up defensive positions on the Pusan Perimeter southern flank west of Masan. By August 15, the 25th Infantry Division had moved into these positions. Rough terrain west of Masan limited the choice of the positions. The mountain group west of Masan was the first readily defensible ground east of the Chinju Pass. The mountain ridges of Sobuk-san dominated the area and