As a prelude to PEGASUS, the 3d MarDiv launched a regimental-size, diversionary attack in eastern Quang Tri Province. On 30 March, Task Force KILO, comprised of the 2d Battalion, 4th Marines; the U. S. Army 3d Squadron, 5th Cavalry; and the 3d Battalion, 1st ARVN Regiment pushed northward from Dong Ha on a search and destroy sweep through the Gio Linh coastal plain area between the Cua Viet River and the DMZ. In addition, a company from the 101st Airborne Division was used as a reconnaissance force and to convey a picture of greater weight and diversity of attack. Although the foray was primarily designed to confuse the NVA and draw attention away from the mailed fist which was poised at Ca Lu, the Allies of Task Force KILO killed 150 North Vietnamese during the first day.(204) At 0700 on D-day (1 April), two battalions controlled by the 1st Marines (2/1 and 2/3), which had moved from Phu Bai to LZ Stud several days before, spearheaded the attack to the west. Meeting only light resistance, 2/1 wheeled to the north of Route 9 and secured its objective while 2/3 swept through and consolidated the area to the south of the road. With both flanks screened by the infantry, the 11th Engineer Battalion began the mammoth task of renovating Route 9. Later in the day, elements of the 3d Brigade (Bde) 1st ACD leapfrogged by helicopter to positions midway between Ca Lu and Khe Sanh. The 1st and 2d Squadrons, 7th Cavalry swarmed into LZ Mike which encompassed Hill 248, approximately 7,500 meters east of the KSCB. This high ground to the south of Route 9 was cradled on three sides by branches of the Quang Tri River. To the north some 3,000 meters, the 5th Battalion, 7th Cavalry air-assaulted the southern slope of Dong Chio Mountain which was designated LZ Cates. This stretch was particularly critical because the road was sandwiched between the Quang Tri River on the south and the nearly perpendicular cliffs which towered menacingly over Route 9 to the north. Following the initial waves, the 3d Brigade Headquarters displaced to LZ Cates and established a CP. By 1650, the Flying Horsemen were in place and continued to expand both zones while 105mm howitzers of the 1st Battalion, 21st Artillery, were helilifted in for direct support. Throughout the PEGASUS area of operations, the Americans established defensive perimeters and passed the night with little or no contact.(205)