General Milburn ordered his lone reserve, the US 15th Infantry, 3rd Division, out of its assembly on the northwest outskirts of Seoul into positions behind the ROK to block a secondary road, Route 1B, which if the PVA reached would afford them an easy path to Route 1 and Seoul. Milburn shortly diverted the 1st Battalion of the 15th to clear Route 2X, a lateral secondary road connecting Route 1 to Route 3 at Uijeongbu, after receiving a report that 250 infiltrating PVA had set up a roadblock about west of Uijeongbu. The 1st Battalion located the PVA force at 18:00, killing 20 before the remaining PVA broke away into nearby hills. With darkness approaching, the battalion commander elected to await morning before attempting to clear the surrounding area. Meanwhile, as General Milburn committed his only reserve unit, air observers and agents working in the area along Route 1 above the Imjin reported enemy forces moving south toward the river. I Corps appeared ready to open its supporting attack along the west flank of the main PVA drive. Well before daylight on the 25th General Milburn became convinced that I Corps would have to give up the Kansas Line. As suspected, KPA I Corps was joining the offensive, although its initial move ended abruptly when its 8th Division attempted to cross the Imjin over the railroad bridge near Munsan-ni and was blown back with high losses from artillery fire and air attacks. However the PVA 190th and 192nd Divisions attacking in strength just after midnight drove the ROK 1st Division back another before giving respite, widening still more the gap between the ROK and Glosters. The 189th Division continued, if slowly, to pass through the gap. Before midnight the entire front of the 3rd Division was under assault. By dark on the 24th there had been no enemy action against the 7th Infantry deployed along Route 33 at the right of the 3rd Division. With the sector quiet, the 1st Battalion, 7th Infantry, had no difficulty in replacing the 3rd Battalion, 65th Infantry, at the center of the regimental front in mid-afternoon to allow the latter to join its regiment near the 29th British Brigade command post in preparation for the scheduled attack to relieve the Gloster battalion. But after unproductive opening attacks on the 65th Infantry and Philippine 10th Battalion Combat Team and a slow approach to the Kansas