Of concern to Van Fleet after US I Corps pulled back from the Imjin was the possibility that PVA/KPA forces would cross the Han River estuary unseen west of Munsan-ni and sweep down the Kimpo peninsula behind Seoul, overrunning Inchon, Kimpo Airfield and Seoul airport in the process. On 25 April he had asked the commander of the west coast group of the United States Navy Task Force 95 to keep the possible crossing site under surveillance, and on the 26th planes from the group's carriers began to fly over the area while in transit to and from close support targets. The cruiser meanwhile steamed for the Inchon area from the Sea of Japan to provide gunfire support. PVA/KPA forces reaching the I Corps' phase line after dark on the 26th attacked in each division sector except that of the 24th on the Corps' right. On the front of the 25th Division, the PVA concentrated an assault between two companies of the 27th Infantry, some reaching as far as behind the line before regimental reserves contained them. A radar-directed bomb strike brought down at the point of penetration and ground fire delivered under light provided by a flare ship eliminated the PVA force. In a repetition of the pattern of PVA/KPA attacks on I Corps' Delta front the previous night, the hardest assaults struck the ROK 1st Division and 65th Infantry at the left of the 3rd Division's position west of Uijeongbu. Artillery fire and air strikes helped contain penetrations of the 65th's line and forced the PVA to withdraw. PVA attacking the 15th Regiment at the right of the ROK 1st Division's line forced a withdrawal before the ROK were able to block the advance. attacking down Route 1 against the 11th Regiment and against the tank destroyer battalion west of the road broke through the lines of both units and took a particularly high toll of tank destroyer troops before ROK counterattacks supported by US tanks stopped the advance. At 06:00 on the 27th, the 24th Division passed to IX Corps' control, as had been directed by General Van Fleet, and what had been the boundary between the 24th and 25th Divisions became the new Corps' boundary. Shortly afterward, General Milburn ordered his remaining forces to withdraw to the next phase line, which would be the last occupied by I Corps before it moved onto the Golden Line.