to help the 1st Marine Division and, in particular, to reinforce the support being given the ROK 6th Division by the New Zealand artillery; Company C, 2nd Chemical Mortar Battalion; and the division's own 27th Field Artillery Battalion. The Corps' latest ground gains had opened Route 17 in the 1st Marine Division's sector far enough north to allow use of a twisting, narrowly confined valley road branching west off Route 17 near the village of Chich’on-ni into the ROK 6th Division's rear area. The 92nd Armored Field Artillery Battalion moved up Route 17 and out the minor road to the west edge of the Marine sector from where its 155mm. self-propelled howitzers could support both the Marines and the ROK. The 987th Armored Field Artillery Battalion and 2nd Rocket Field Artillery Battery, both equipped with 105mm. howitzers, used the winding valley road to reach the right half of the ROK sector, where they took position behind the 7th Regiment near the ROK artillery and US 4.2-inch mortars. For reasons that never became clear, the ROK 2nd and 19th Regiments failed to develop the defensive positions ordered by General Chang. With numerous gaps and open outside flanks, the division front was vulnerable to infiltration, and the nearby reserves were almost as subject to attack as were the forward units. Forces of the PVA 60th Division, 20th Army, hit Chang's lines about 20:00. Without artillery support and with little other supporting fire, units of the 179th Regiment, 60th Division, struck the inside battalion of the 2nd Regiment. Forces following punched through a central gap, some veering west and east behind the 19th and 2nd Regiments, others continuing south toward the 7th Regiment. Within minutes both line regiments were in full flight. Caught up in the rush of troops from the 2nd Regiment, the 7th Regiment joined the wild retreat. Abandoned weapons, vehicles, and equipment littered vacated positions and lines of drift as the South Koreans streamed south, east, and west, rapidly uncovering the fire support units. The New Zealand artillery supporting the 19th Regiment in the west managed to withdraw with guns and equipment intact down the Kapyong River valley to a position north of the British 27th Brigade assembled near Kapyong town. To the east, PVA following the 2nd and 7th Regiments caught the ROK 27th Field Artillery Battalion in position. Under fire, its members abandoned guns and joined the southerly