By 0730 on the morning of 25 June, the operation, codenamed Jay, was ready to begin. Colonel Sherman had opened his forward CP in the objective area and the 3d Battalion, 12th Marines artillery, consisting of a 105mm battery and a 155mm battery, was in place. To the north, two ARVN battalions were in position across the 0 Lau. At 0800, under clear skies, the first wave of 19 CH-46s from MAG-16, carrying the lead elements of the 2d Battalion, 4th Marines, started their descent into Landing Zone Raven, approximately 8,000 meters north of the 4th Marines' command post. After some delay, the Marine helicopters completed the lift of the remainder of Kelley's battalion without incident at 0945. One half hour later, the battalion crossed its line of departure with Company F on the north side of Route 597, Company H on the south of the road, and the command group and Company E following in trace.
The terrain in the objective area consisted of dry paddy land interspersed with several streams and lagoons. Despite the relatively flat, open ground in the region, paddy dikes and thick stands of bamboo, hedgerows, and scrub growth, as well as extensive tree lines surrounding the hamlets, provided excellent cover and concealment for any defending enemy force.
Kelley's battalion, nevertheless, reached its first objective, Phase Line Bravo, some 2,000 meters southeast of LZ Raven, without encountering any opposition. As the Marines renewed their advance, however, the enemy opened up with heavy small arms fire from Ap Chinh An, the same fortified hamlet that had caused such frustration for the 1st Battalion, 4th Marines earlier in Operation Oregon. The Marine attack soon stalled. Lieutenant Colonel Kelley then ordered his Company H to swerve north in order to flank the enemy and at the same time asked for naval gunfire, artillery, and air support. Despite the employment of the supporting arms, the Marine battalion still was unable to penetrate the enemy defenses.
Lieutenant Colonel Hanifin's 2d Battalion, 1st Marines, meanwhile, had arrived at 1100 in its landing zone, LZ Shrike, approximately 9,000 meters southeast from 12 Raven. As planned, the battalion then established its blocking positions at Phase Line Delta, some 3,500 meters northwest of its 12. At 1420, Colonel Sherman ordered Hanifin to move his battalion into new positions at Phase Line Golf, another 1,500 meters to the northwest to rein \force Kelley's battalion. As the 2d Battalion, 1st Marines advanced with Company G on the north side of Route 597 and Company H on the south, the Marines met strong enemy forces in the hamlet of My Phu. While still taking fire from its front, Company H deployed to rescue the crew of a downed helicopter.
Marine helicopter from HMM-161 which had crashed 1,000 meters south of the hamlet. Lieutenant Colonel Hanifin then ordered his Company F to reinforce Company G in the attack on My Phu. After accomplishing its rescue mission, Company H then maneuvered to link up with Kelley's battalion.
Through the night and early morning hours of 25-26 June, both battalions continued to encounter heavy resistance in the two hamlets. With two of his companies engaged in Ap Chinh An, Lieutenant Colonel Kelley ordered his Company E to advance southeast and attempt to reach Hanifin's battalion. Although the Marines of Company E could see the men of Company H of the 1st Marines battalion, they were unable to break through the enemy lines to make physical contact. From well dug-in positions in both hamlets, the enemy defenders, employing 60mm, 80mm, and 81mm mortars, heavy automatic and small arms weapons, fought tenaciously. At 2100, the NVA made a strong counterattack against Company H, 4th Marines, south of Ap Chinh An, but with the assistance of supporting arms the Marines repulsed the assault. Despite problems with coordination because of the proximity of the two Marine battalions to one another, Marine aircraft and artillery reinforced by the guns of the destroyer Davis (DD 957) repeatedly bombarded the enemy positions in the two hamlets. The Davis alone fired more than 530 rounds on the 25th. Believing they had the enemy force hemmed in between them, the two Marine battalions waited for daylight before renewing their attacks on Ap Chinh An and My Phu.
There were two other separate but related actions on the night of 25-26 June. At the request of the U.S. sector advisor, Colonel Sherman sent his reserve force, Company I, 3d Battalion, 4th Marines, together with a section of Ontos to reinforce a South Vietnamese Popular Force platoon some 5,000 meters northwest of the 4th Marines CP. As they reached the objective areas, the Marines received some scattered shots and returned the fire. The VC force quickly disengaged, leaving eight dead behind. Further north, a strong NVA force, suspected to be from the 806th Battalion, assaulted the two ARVN battalions in Lam Son-284. U.S. supporting arms broke up the attack. According to a Marine report, 'two large secondary explosions were observed and the VC appeared to be running in confusion'.
On the morning of 26June, the 4th Marines made its preparations for the final assault on Ap Chinh An and My Phu. Colonel Sherman reinforced Lieutenant Colonel Kelley's battalion at 0655 with another company, Company L, 3d Battalion, 4th Marines. After a preliminary artillery and air bombardment, the two battalions launched their attacks. Although the Marines met resistance in both hamlets, it was soon apparent that the bulk of the enemy forces had pulled out during the night, leaving behind a rear guard to hamper the progress of the Marines. With the assistance of supporting arms, the Marine infantry slowly but surely cleared out the remaining enemy.The most serious incident occurred when a misdirected Marine 105mm shell fell on a 2d Battalion, 4th Marines company CP, killing one Marine and wounding three others. At 1600, Company E, 2d Battalion, 4th Marines, linked up with the 2d Battalion, 1st Marines, and Lieutenant Colonel Kelley relinquished operational control of the company to Lieutenant Colonel Hanifin. By nightfall, the Marine battalions had captured the two hamlets.
Through 28 June, the two Marine battalions continued with the mop-up in their respective sectors. In My Phu, the 2d Battalion, 1st Marines, 'swept and re-swept . . . with only civilians and hidden bodies remaining in the objective area'. Lieutenant Colonel Kelley's battalion in Ap Chien An also came across 'some bodies and equipment . . . in various hiding places'. Both the Marines and the NVA had sustained heavy losses during the fighting. From 25-28 June, the two Marine battalions took casualties of 23 dead and 58 wounded, with all but 'two of the deaths and seven of the injuries having occurred in the initial fighting of 25 June. The Marines recovered 82 bodies of the enemy and estimated killing 200 more'.
On 28June, Colonel Sherman received permission to make Jay a one-battalion operation. He directed that Lieutenant Colonel Hanifin's battalion close out its portion of the operation and that the 2d Battalion, 4th Marines take over the entire sector in the Ap Chien An-My Phu village complex. Although on the night of the 28th the regiment received intelligence that a VC force was about to attack the command post, the attack never materialized and the Marines continued with their plans to reduce the scope of the operation. On the morning of the 29th, Lieutenant Colonel Kelley assumed control of the 2d Battalion, 1st Marines sector while the latter unit prepared to depart for the regimental CP. Company E, 2d Battalion, 4th Marines reverted to the operational control of its parent battalion and Company L, 3d Battalion, 4th Marines returned to the 4th Marines CP as part of the regimental reserve. In the artillery area, the 3d Battalion, 12th Marines made its preparations to leave for Phu Bai. The Marine artillerymen had staged their non-essential vehicles for departure when shortly after 0830:The sounds of automatic small arms and mortar firing were heard in the CP. Two large columns of smoke [rose] . in the air. The Battalion S-3 immediately ordered action rear on all weapons in anticipation of some fire missions.
The allied intelligence of the movement of an enemy battalion into the Jay area of operations had not been entirely a false alarm. On the night and early morning hours of 28-29 June, the 802d VC Battalion departed its base area in the mountains southwest of the Marine operating area and at 0200 reached its destination on Route 1, some 2,500 meters northwest of the 4th Marines CP. Its target, however, was not the Marines' CP, but rather a South Vietnamese Marine truck convoy, due to pass by later in the morning. Armed with 75mm and 57mm recoilless rifles, 60mm mortars, and automatic weapons, the VC battalion deployed along both sides of the road and waited.
The South Vietnamese convoy of 28 trucks carrying the 2d Battalion, Vietnamese Marine Corps left Hue City at 0730. Loaded on board the vehicles by company, the 1st Company was at the head of the column; the 3d Company, H&S Company, and the command group were in the center; and the 2d and 4th Companies brought up the rear. Although there had not been an ambush along this sector of Highway 1 for more than 10 months, the South Vietnamese troops faced outward and automatic weapons on the trucks were at the ready. The battalion commander provided for planned artillery coverage along the route of march and kept an artillery forward observer with him. For added insurance, a small South Vietnamese spotter plane flew overhead.. In the event of an ambush, the battalion was 'to dismount, form up by units, and stand and fight as . . . directed'.
About 0830, the Vietnamese truck convoy crossed the bridge over the 0 Lau River at Phong Dien and continued north. As the first echelon drove past an open 3,000-meter area, enemy gunners on the west side of the road opened up at a range of 200 meters 'with a heavy volume of accurate mortar and recoilless rifle fire' at the center of the convoy. The enemy infantry then joined in with machine gun and rifle bursts directed along the entire length of the column. Ten of the trucks were hit; three were completely destroyed. The battalion commander halted the convoy and ordered his troops to dismount. Marine Captain Thomas E. Campbell, the senior U.S. advisor to the 2d Battalion, remembered that despite heavy casualties the Vietnamese Marines accomplished this in good order and deployed along the road, returning the enemy fire.
The side of the road offered very little cover and the Marines continued to take casualties. Campbell recalled that they could see through the thin stand of trees to the west of the highway the 'back blasts from the recoilless weapons along the crest of the low rolling hills', and enemy troops maneuvering forward. The Marine battalion commander ordered his companies to move back to the relative security of the railroad tracks which paralleled the highway, some 75 meters to the east. As the Marines, led by the H&S Company and command group, together with the 2d and 4th Companies, approached the railroad cut they were met with a 'withering volume of small arms fire and hand grenades'. Up to this point, all of the enemy activity had been from west of the highway and the two VC companies east of the road had allowed the Marines to come within 10 yards of their positions before opening fire. The Vietnamese Marine battalion commander was seriously wounded and 'virtually the entire command group was killed outright or incapacitated by wounds'. Some 15-20 Marines from the H&S Company reached the railroad cut but were mowed down by machine gun fire 'directed down the railroad tracks and into their left flank'. The enemy had succeeded in dividing the Marine battalion into two, one group centered around the 2d and 4th Companies together with the remnants of the H&S Company, and the second group consisting of the 1st and 3d Companies, some 500 yards away. Less than six minutes had elapsed since the ambush had been triggered.
The Marines were relegated to maintaining two perimeters, separated by open ground and not mutually supporting. Fortunately for the embattled troops, a U.S. Army spotter plane arrived overhead. The U.S. Marine advisors on the ground made radio contact with the pilot and called for assistance. At this point, the 3d Battalion, 12th Marines, which had been monitoring the U.S. Marine advisor radio net, broke in and offered its services. The first artillery shells fell into the impact area at 0846. About this time a U.S. Air Force FAC(A) aircraft was on the scene and began to direct Marine F-4s, which had been circling overhead, into strikes on the enemy positions.
Shortly afterward, both the 4th Marines and the ARVN 1st Division began preparations to send reinforcements to assist the beleaguered South Vietnamese Marine battalion. At 0915, Colonel Sherman, together with members of his staff and one of his company commanders, made an aerial reconnaissance of the ambush site and on his return ordered his reserve company accompanied by an Ontos platoon into the area. The ARVN division, which had been conducting a new operation, Lam Son-285, a few miles north of the ambush, sent two infantry battalions -reinforced by an APC troop and tank company.
At the ambush site, once the American aircraft began their strikes, the 802d Battalion lost interest in the South Vietnamese Marines and concentrated on making good its escape. To the east of the railroad, the enemy troops had the advantage of thick cover and were able to get out relatively unscathed. To the west of Highway 1, however, the VC had to cross largely open ground before they could reach the relative security of the hills. Marine artillery and air enjoyed a field day while the Ontos platoon, which arrived in the area shortly after 0950, 'obliterated a VC squad on a ridgeline with a single 106mm salvo'.
Within one and one-half to three hours after the ambush, two Marine companies, I and L, 3d Battalion, 4th Marines; the Ontos platoon; and the 1st ARVN Division units, reinforced by an airborne battalion, had converged on the objective area and cut off the retreat of those enemy forces still west of the highway. Between them, the allies killed more than 185 of the enemy and captured nine prisoners. They also recovered 39 individual and eight crew-served weapons. One Marine recalled that 'General Walt directed his own helicopter to land and capture a 75mm recoilless rifle abandoned by retreating VC'.
The victory over the 802d had not come cheaply. The 2d Vietnamese Marine Battalion sustained casualties of 42 killed, including the battalion commander who died of his wounds, and 95 wounded. Captain Campbell, who had also been wounded in the action, later wrote that the reasons that the battalion had not suffered even more grievous losses were the:
. . maintenance of unit integrity, the skillful maneuvering of these companies by their commanders, and the outright doggedness, determination, and raw courage of individual Marines
Operation Jay continued for a few more days, but the fighting was over. The two Marine companies and the Ontos platoon, which participated in the action of the 29th in support of the Vietnamese Marine battalion, returned to the 4th Marines CP the following morning. On the 30th, Lieutenant Colonel Hanifin's 2d battalion also departed for Phu Bai. The following day, Colonel Sherman closed his CP in the Jay operation and, on 2 July, the 2d Battalion, 4th Marines completed its mop up and civic action activities in the Ap Chien An and My Phu complex. During the eight-day operation, the Marines and ARVN, supported by Marine air and artillery, and naval gunfire, smashed three enemy battalions, the 802d, 806th, and 812th. Marine estimates of the enemy dead in both Jay and in the reaction to the Vietnamese Marine ambush, not including those killed by the ARVN, were more than 475. Allied intelligence later learned that the 812th literally ceased to exist, with its remaining personnel distributed among three other battalions.
Following Jay, the Marines also made an attempt to finish off the 802d Battalion, which allied intelligence believed had returned to its base area south of the old Florida area after the ambush on 29 June. Colonel Sherman assigned the operation to his 3d Battalion, which after completing Operation Athens exchanged TAORs with the 1st Battalion and had become the regimental reserve. The plan was for the Marine battalion, supported by air and artillery, to exploit a B-52 strike on the suspected enemy base camp. As planned, the 3d Battalion began the operation, codenamed Holt, on 2 July, but enjoyed meager results. For the next few days through the end of the operation on 6 July, the Marines killed seven of the enemy at the cost of one wounded Marine. The battalion had most of its difficulty with the dense foliage, which often limited its progress to a pace of 50-100 yards per hour. As one Marine officer observed, 'Holt was not particularly inspiring', but it gave the Marines a taste of jungle warfare that they were soon to encounter farther north.