1st Division SSI
|Branch||Army of the Republic of Vietnam|
|Part of||I Corps|
Tôn Th?t ?ính
Nguy?n V?n Thi?u
Nguy?n Chánh Thi
Nguy?n V?n Chuân
Pham Xuan Nhuan
Ngô Quang Trng
Ph?m V?n Phú
The 1st Division of the Army of the Republic of Vietnam (ARVN)—the army of the nation state of South Vietnam that existed from 1955 to 1975—was part of the I Corps that oversaw the northernmost region of South Vietnam, the centre of Vietnam.
The 1st Division was based in Hu?, the old imperial city and one of two major cities in the region, which was also the corps headquarters. Until late 1971 the Division was also tasked with the defence of Qu?ng Tr?, the closest town to the Vietnamese Demilitarized Zone (DMZ) and among the first to be hit by the Tet Offensive.
In 1960 the 1st Field Division was redesignated the 1st Infantry Division.:298
In late 1965 Maj. Gen. Lewis William Walt, the commander of the US III Marine Amphibious Force and the I Corps' senior adviser, assessed the Division under General Nguy?n V?n Chuân as "waging a skillful campaign" and "consistently destroying the VC in all significant encounters.":113
On 12 March 1966 following the dismissal of General Nguy?n Chánh Thi as I Corps commander due to his handling of the Buddhist Uprising, General Chuân was appointed as the new I Corps commander and General Pham Xuan Nhuan, the head of the Ranger Command in Saigon, was given command of the Division.:129 Following the dismissal of Thi, the northern zone erupted into a seething inferno of political dissent. The number and intensity of strikes, marches, and rallies steadily increased, fueled by soldiers, police, and local officials loyal to Thi. By the beginning of April Struggle Movement forces appeared to control most of Hu?, Da Nang and Hoi An and had the support of the I Corps headquarters and the Division. At the same time, South Vietnamese combat operations in the northern zone began to peter out, and the danger that the crisis presented to the war effort became evident.:130 As the new Division commander, General Nhuan placed infantry and armored forces in blocking positions along Route 1, between Hu? and Da Nang, and stood ready to reinforce Struggle units in Da Nang the situation inside the city was tense. The commander of the Quang Nam Special Zone, Col. Dam Quang Yeu, headed the rebel military units that, according to US estimates, included an infantry battalion from the 51st Regiment, three Regional Forces companies, eleven Popular Forces platoons, and six armored vehicles, plus about 6000 South Vietnamese administrative troops and 200 military police. When Yeu quickly positioned some of his units on the approaches to the downtown area, the start of civil war seemed imminent.:132
On 10 June 1966 the South Vietnamese junta began a steady buildup of special riot police under Republic of Vietnam National Police commander Colonel Nguy?n Ng?c Loan on the outskirts of Hu? and, on 15 June, sent a task force of two Airborne and two Marine battalions under Colonel Ngô Quang Trng into the city for a final showdown. Intermittent fighting lasted in Hu? for four days. Opposition was disorganized and consisted of about 1000 Division troops, mostly soldiers from support units. Protected by Trng's forces, Loan's police removed the Buddhist altars and arrested most of the remaining leaders of the Struggle Movement, including Thích Trí Quang. The junta gave Trng command of the Division, and by the end of June both the Division and Hu? were under firm government control.:143 By 1967 US advisers reported that General Trng had whipped the formerly rebellious Division into one of South Vietnam's best army units.:248
In mid-July 1966 the Division launched Operation Lam Son 289 in support of the US 3rd Marine Division's Operation Hastings in the southern DMZ. The Division lost 21 killed in the operation.:160-176
On 25 May near Thong Nghia (:309-10) the 2nd Regiment engaged a PAVN battalion killing 122 PAVN. The next day the Regiment killed another 110 PAVN while losing 2 killed.
On 8 August the 2nd Regiment engaged a PAVN force from the 1st Battalion, 138th Regiment 2km east of Gio Linh killing over 100 and forcing them to withdraw towards the DMZ.:387 On the morning of 15 August the 2nd Regiment and the US 11th Armored Cavalry Regiment, supported by Company A, 1st AMTRAC Battalion launched an assault into the southern DMZ which resulted in a reported 421 PAVN killed.:387
On 23 October the 2nd Regiment supported by Company H, 9th Marines and a tank platoon from Company A, 3rd Tank Battalion launched a raid into the DMZ north of Ha Loi Trung ( ), resulting in 112 PAVN killed.:395
During the Battle of Hue, the division fought the entirety of the battle while its Mang Ca Garrison, headquarters in the northeast corner of the Citadel was completely surrounded. In the early morning hours of 31 January 1968, a division-sized force of PAVN and VC soldiers launched a coordinated attack on the city of Hu? breaking through the western wall of the Citadel. On the Tây L?c Airfield, the Division's elite Hac Bao (Black Panther) Company, reinforced by the 1st Division's 1st Ordnance Company, stopped the PAVN 800th Battalion. The 802nd Battalion struck the 1st Division headquarters at Mang Ca. Although the PAVN battalion penetrated the division compound, an ad hoc 200-man defensive force of staff officers and clerks staved off the enemy assaults. General Trng called back most of his Black Panther Company from the airfield to bolster the headquarters defenses, which kept division headquarters secure.:167 General Trng called in reinforcements ordering his 3rd Regiment; the 3rd Troop, 7th ARVN Cavalry; and the 1st ARVN Airborne Task Force to relieve the pressure on Mang Ca. Responding to the call at PK-17 base 17 km north of Hu?, the 3rd Troop and the 7th Battalion of the Airborne task force rolled out of their base area in an armored convoy onto Highway 1. A PAVN blocking force stopped the ARVN relief force about 400 meters short of the Citadel wall. Unable to force their way through the enemy positions, the South Vietnamese paratroopers asked for assistance.:168 The 2nd ARVN Airborne Battalion reinforced the convoy, and the South Vietnamese finally penetrated the lines and entered the Citadel in the early morning hours of 1 February. The cost had been heavy: the ARVN suffered 131 casualties including 40 dead, and lost four of the 12 armored personnel carriers in the convoy. The ARVN claimed to have killed 250 PAVN, captured five prisoners, and recovered 71 individual and 25 crew-served weapons.:168 The 2nd and 3rd Battalions, 3rd Regiment, advanced east from encampments southwest of the city along the northern bank of the Perfume River, but PAVN defensive fires forced them to fall back. Unable to enter the Citadel, the two battalions established their night positions outside the southeast wall of the old City. PAVN/VC forces surrounded the 1st and 4th Battalions of the regiment, operating to the southeast, as they attempted to reinforce the units in Hu?. Captain Phan Ngoc Luong, the commander of the 1st Battalion, retreated with his unit to the coastal Ba Long outpost. At Ba Long, the battalion then embarked upon motorized junks and reached the Citadel the following day. The 4th Battalion, however, remained unable to break its encirclement for several days.:168 South of the city, Lieutenant Colonel Phan Hu Chi, the commander of the 7th Armored Cavalry Squadron attempted to break the PAVN/VC stranglehold. He led an armored column toward Hu?, but like the other South Vietnamese units, found it impossible to break through. With the promise of U.S. Marine reinforcements, Chi's column, with three tanks in the lead, tried once more. This time they crossed the An Cuu Bridge over the Phu Cam Canal ( ) into the new city. Coming upon the central police headquarters in southern Hu?, the tanks attempted to relieve the police defenders, but an enemy B-40 rocket made a direct hit upon Lieutenant Colonel Chi's tank, killing him instantly. The South Vietnamese armor pulled back.:168 At 15:00, the 1st Battalion, 3rd Regiment reached the Mang Ca compound. Later that day, U.S. Marine helicopters from HMM-165 brought part of the 4th Battalion, 2nd Regiment from ?ông Hà Combat Base into the Citadel. The deteriorating weather forced the squadron to cancel the remaining lifts with about half of the battalion in the Citadel.:176
The ARVN would attempt to regain the Citadel while the Marines regained the new city south of the Perfume River. Within the Citadel the ARVN 1st Battalion, 3rd Regiment and the 1st Airborne task force cleared out the north and western parts of the Citadel including Tây L?c Airfield and the Chanh Tay Gate, while the 4th Battalion, 2nd Regiment moved south from Mang Ca towards the Imperial Palace, killing over 700 PAVN/VC by 4 February. On 5 February General Trng exchanged the Airborne with the 4th Battalion, which had become stalled. On 6 February the 1st Battalion captured the An Hoa Gate on the northwest corner of the Citadel and the 4th Battalion captured the southwest wall. On the night of the 6th, the PAVN counterattacked, scaling the southwest wall and pushing the 4th Battalion back to Tây L?c. On the 7th General Trng ordered the 3rd Regiment, which had been futilely trying to break into the southeast corner of the Citadel to move to Mang Ca to reinforce his units inside the Citadel.:192 On 11 February the Vietnamese Marines Task Force A comprising the 1st and 5th Battalions, began to be lifted by helicopter into Mang Ca to replace the Airborne, however due to poor weather this deployment would not be completed until 13 February. General Trng called for assistance in clearing the Citadel and at 10:45 on 11 February Company B, 1st Battalion, 5th Marines was airlifted aboard Marine CH-46s into Mang Ca, however enemy fire forced several of the helicopters to return to Phu Bai. The Marines together with 5 M48s from the 1st Tank Battalion would later be loaded onto Mike Boats at the LCU Ramp in southern Hue and ferried across to Mang Ca.:197 On 14 February the Vietnamese Marine Task Force A joined the battle. The operational plan was for the Marines to move west from Tây L?c and then turn south, however they were soon stopped by strong PAVN defenses; after two days the Vietnamese Marines had only advanced 400 metres. Meanwhile, the ARVN 3rd Regiment fought off a PAVN counterattack in the northwest corner of the Citadel.:204 On 17 February the Vietnamese Marines and 3rd Regiment resumed their attacks south, while the Black Panther Company was moved to support the right flank of the 1/5 Marines, over the next 3 days these forces would slowly reduce the PAVN's perimeter.:206 On 22 February after a barrage of 122mm rockets the PAVN counterattacked the Vietnamese Marines who pushed them back with the support of the Black Panther Company. On the night of 23 February the PAVN attempted another counterattack but were forced back by artillery fire and the 3rd Regiment launched a night attack along the southern wall of the Citadel, at 05:00 they raised the South Vietnamese flag on the Citadel flag tower and proceeded to secure the southern wall by 10:25. General Trng then ordered the 2nd Battalion 3rd Regiment and the Black Panther Company to recapture the Imperial City and this was achieved against minimal resistance by late afternoon. The last remaining pocket of PAVN at the southwest corner of the Citadel was eliminated in an attack by the 4th Vietnamese Marine Battalion in the early hours of 25 February.:210-11 As a result of the battle this division had earned several commendations from the RVN Government as well a US Presidential Unit Citation.
Launched simultaneously with the attack on Hue the PAVN/VC also attacked Quang Tri on the early morning of 31 January. The PAVN 812th Regiment (reinforced), of the 324th Division was tasked with capturing the city. The brunt of the attack would fall on the ARVN forces in and around the city. These were the 1st Regiment, 1st Division, the 9th Airborne Battalion, 2nd Troop, 7th Cavalry an Armored Personnel Carrier (APC) Troop attached to the 1st Regiment, the Republic of Vietnam National Police, a paramilitary body led by regular military officers stationed within the city, and Regional and Popular Force (militia) elements in the city. The 1st Regiment had two of its battalions in positions to the north of the city, and one to the northeast, protecting pacified villages in those areas. The Regiment's fourth battalion was in positions south of the city in and around the regiment's headquarters at La Vang Base. One Airborne company was bivouacked in Tri Buu village on the northern edge of the city with elements in the Citadel, and two Airborne companies were positioned just south of the city in the area of a large cemetery where Highway 1 crosses Route 555.:51
Qu?ng Tr? City was clear of PAVN/VC troops by midday on 1 February, and ARVN units with U.S. air support had cleared Tri Buu Village of PAVN troops. The remnants of the 812th, having been hit hard by ARVN defenders and American air power and ground troops on the outskirts of the city, particularly artillery and helicopters,:56 broke up into small groups, sometimes mingling with crowds of fleeing refugees, and began to exfiltrate the area, trying to avoid further contact with Allied forces. They were pursued by the American forces in a circular formation forced contact with the fleeing PAVN/VC over the next ten days.:56 Heavy fighting continued with large well-armed PAVN/VC forces south of Qu?ng Tr? City, and there were lighter contacts in other areas. This pursuit continued throughout the first ten days of February.:57
The US military considered the attack on Qu?ng Tr? "without a doubt one of the major objectives of the Tet Offensive". They attributed the decisive defeat to the hard-nosed South Vietnamese defense, effective intelligence on PAVN/VC movements and the air mobile tactics of the 1st Cavalry Division. Between 31 January and 6 February, the Allies killed an estimated 914 PAVN/VC and captured another 86 in and around Quang Tri.:57 The successful defense of Quang Tri prevented reinforcement at Hue, as well as preventing the further collapse of security in the region.
On 28 April at the start of the May Offensive the Division's Hac Bao Company located the 8th Battalion, 90th Regiment in the fishing hamlet of Phuoc Yen 6 km northwest of Hu?. Units from the 1st and 2nd Battalions, 501st Infantry Regiment surrounded the hamlet and destroyed the battalion in a 4 day long battle. PAVN losses 309 killed (including all the senior officers) and 104 captured.:538 On 2 May a Regional Force company reported that PAVN were in the hamlet of Bon Tri, 6 km west of Hu? that had been used as a supply station during the Battle of Hu?. Several companies from the 1st Battalion, 505th Infantry Regiment and the Hac Bao Company engaged the PAVN 3rd Battalion, 812th Regiment in a 2 day battle resulting in 121 PAVN dead for Allied losses of 4 killed and 18 wounded.:538
On 29 April the PAVN 320th Division attacked An Binh, north of ?ông Hà Combat Base, this drew two Battalions of the 2nd Regiment into a running battle and the 1st Battalion 9th Marines was sent in to support the ARVN resulting in a 7-hour long battle that left 11 Marines, 17 ARVN and over 150 PAVN dead.:292 On 30 April, a PAVN unit opened fire on a US Navy Clearwater patrol from entrenched positions near Dai Do, 2.5 km northeast of ?ông Hà. It was later discovered that four PAVN Battalions including the 48th and 56th from the 320th had established themselves at Dai Do.:294 The Battle of Dai Do lasted until 3 May and resulted in 81 Marines, 5 ARVN and over 600 PAVN killed.:295-304 On 26 May the 2nd Regiment killed 110 PAVN north of Thuong Nghia.:309
From 4-20 August 1968 the Division participated in Operation Somerset Plain a spoiling attack on the PAVN logistics hub in the A S?u Valley with the 1st Brigade, 101st Airborne Division. The US/ARVN forces proceeded to search the valley meeting only scattered resistance until 10/11 August when the ARVN 3rd Battalion, 1st Infantry Regiment was attacked by elements of the PAVN 816th and 818th Main Force Battalions. Air and artillery support was called in and the PAVN retreated into the jungle losing several dozen killed. The Division lost 11 killed while the PAVN lost 181 killed and 4 captured.:607-8
From 10-20 September 1968, the 2nd and 3rd Battalions, 54th Regiment participated in Operation Vinh Loc a security operation on Vinh Loc Island ( ), Phú Vang District, east of Hu? with the 2nd Brigade, 101st Airborne Division. VC losses were 154 killed, 370 captured and 56 Chieu Hoi.:206-8
From 10 May to 7 June 1969 the 1st and 3rd Regiment participated in Operation Apache Snow with the US 101st Airborne Division in the A Sau valley.  During this operation the 3rd Regiment participated in the Battle of Hamburger Hill. ARVN losses were 31 killed while PAVN losses were 675 killed and 3 captured.
From 26 May to 7 November 1969 the 1st and 2nd Battalions, 51st Regiment participated in Operation Pipestone Canyon with the 37th Ranger Battalion and the US 1st Marine Division against PAVN/VC base areas on Go Noi Island southwest of Da Nang.:175-87
At the end of 1969 Maj. Gen. Melvin Zais, commanding US XXIV Corps in I Corps, proposed breaking up the Division (with four regiments and about nineteen combat battalions) into two divisions controlled by a "light corps" headquarters responsible for the defense of the DMZ area, but his immediate superior, Lt. Gen. Herman Nickerson Jr. (USMC), commanding the III Marine Amphibious Force (and the I Corps senior adviser), and General Lãm, the I Corps commander, both vetoed the idea, citing the lack of enough experienced Vietnamese officers to staff a new command.:382
From 1 April to 5 September 1970 the Division participated in Operation Texas Star with the US 101st Airborne Division in Qu?ng Tr? and Th?a Thiên Provinces. In late July 1970 following the Battle of Fire Support Base Ripcord, the PAVN 6th Regiment attacked the 1st Regiment's Firebase O'Reilly ( ) 8km north of Ripcord. General Trng reinforced O'Reilly with another Regiment and the ARVN defended the base for 2 months before abandoning it and Firebase Barnett in September.
From 5 September 1970 to 8 October 1971 the Division participated in Operation Jefferson Glenn with the US 101st Airborne Division to patrol the PAVN/VC rocket belts that threatened Hu? and Da Nang.
From 8 February to 25 March 1971 the Division troops participated in Operation Lam Son 719. They developed a series of firebases along the south Route 9 in Laos to screen the southern flank of the ARVN advance.:8-12 On 3 March, elements of the Division were helilifted into two firebases (Lolo and Sophia) and LZ Liz, all south of Route 9. Eleven helicopters were shot down and another 44 were damaged as they carried one battalion into FSB Lolo.:336 Three days later, 276 UH-1 helicopters protected by Cobra gunships and fighter aircraft, lifted the 2nd and 3rd Battalions of the 2nd Regiment from Khe Sanh to Tchepone - the largest helicopter assault of the Vietnam War.:253 Only one helicopter was downed by anti-aircraft fire as the troops combat assaulted into LZ Hope, four kilometers northeast of Tchepone. For two days the two battalions searched Tchepone and the immediate vicinity, but found little but the bodies of PAVN soldiers killed by air strikes. PAVN responded by increasing its daily artillery bombardments of the firebases, notably Lolo and Hope. During the extraction of the 2nd Regiment, 28 of the 40 helicopters participating were damaged.:336-7
In October 1971 the Division's 2nd Regiment and several of its battalions were transferred to the newly formed 3rd Division which assumed responsibility for the defense of the DMZ and Qu?ng Tr? Province.:18-9
The 1st Division's new operational area was south of the Qu?ng Tr?-Th?a Thiên Province boundary and north of the H?i Vân Pass. Its primary responsibility was to defend the western approaches to Hu?. Its 1st Regiment and 7th Armored Cavalry Regiment were deployed at Camp Evans, its 3rd Regiment at Firebase T-Bone ( ) and its 54th Regiment at Firebase Bastogne. Division headquarters were at Camp Eagle southeast of Hu?.:19
In February ARVN intelligence detected that the PAVN 324B Division was moving into the A S?u Valley in western Th?a Thiên Province. The Division moved its units west of Hu? and clashed with PAVN units along Route 547 in early March.:22
The initial thrust of the Easter Offensive fell on the 3rd Division in Qu?ng Tr? Province and the initial PAVN actions in Th?a Thiên Province were designed to keep the 1st Division in place while the PAVN overran Qu?ng Tr?. The 1st Division maintained a strong defense in the foothills west of Hu? holding a line from Camp Evans in the north to Firebase Rakkasan ( ) then southeast through Firebase Bastogne and Firebase Checkmate and then to Firebase Birmingham. The 3rd Regiment was kept in reserve to add depth to the defense. Firebase Veghel had been abandoned at the start of the offensive.:48-9
The areas around Firebases Bastogne and Checkmate straddling Route 547 came under intense pressure from the PAVN 324B Division and by the second week of April both were cut off. On 11 April the 1st Regiment attempted clear Route 547 but was stopped by the PAVN 24th Regiment despite intensive artillery and air support. By late April the situation at the Firebases was increasingly desperate with the defending battalions reduced to 50% effective and medical evacuation increasingly difficult. On 28 April the PAVN 29th and 803rd Regiments attacked Firebase Bastogne overrunning it within 3 hours, destroying much of the 54th Regiment and forcing the defenders to retreat to Firebase Birmingham. The loss of Bastogne forced the abandonment of Firebase Checkmate during the night.:49
On 1 May as the defense of Qu?ng Tr? City disintegrated, PAVN pressure on the 1st Division increased as the PAVN launched an assault on Firebase King northwest of Firebase Bastogne and rocketed Camp Eagle.:50
On 3 May I Corps commander General Hoàng Xuân Lãm was replaced by Lieutenant General Trng, commander of IV Corps and former commander of the 1st Division and this change of command and reinforcement by forces of the general reserve stabilized the ARVN position in Th?a Thiên Province.:50-3 The newly arrived Marine Division was given responsibility for north and northwest Th?a Thiên Province, while the Division was given responsibility for the area southwest and south of Hu? blocking any further PAVN advance from the A S?u Valley.:54
On 15 May the Division launched a helicopter assault on Firebase Bastogne recapturing the base while 2 regiments cleared the high ground between the base and Firebase Birmingham and by 25 May Firebase Checkmate had also been reoccupied by the Division.:57
From 11 to 18 June the Division launched an attack west towards Firebase Veghel to probe PAVN strength ahead of the launch of General Trng's Operation Lam Son 72 to recapture Qu?ng Tr? Province. The main effort would be made by the Airborne and Marine Divisions while the Division would pin down PAVN forces southwest of Hu?.:65
In July the PAVN launched attacks on Firebase Checkmate which changed hands several times and then Firebase Bastogne, capturing both bases. In early August with heavy support from B-52s and reinforced by the independent 51st Regiment, the Division recaptured both firebases and expanded its control of the area, recapturing Firebase Veghel on 19 September.:71-4
In late July 1973 two 3rd Infantry positions west of the Ngoc Ke Trai stream fell to PAVN attack. The pressure continued, and the 3rd Infantry gave up four more outposts along the Song Bo river in late August. Another series of positions along the Ngoc Ke Trai fell in November as signs of deteriorating morale and weak leadership began to appear in the formerly highly respected Division. Casualties resulting from the PAVN assaults were light, and the rapid collapse of the defenses could only be attributed to faltering will and uninspired leadership. At this time Lt. Gen. Lam Quang Thi, I Corps Deputy Commanding General and commander north of the H?i Vân Pass, detached a battalion from the 51st Infantry and returned it to the 1st Division to reinforce the Song Bo defenses. The 1st Division Commander, Brig. Gen. Le Van Than, further reinforced the 3rd Regiment with a battalion of the 1st Infantry Regiment. The line stabilized toward the end of the year, but not until after General Truong had accomplished the removal of General Than and replaced him with Col. Nguyen Van Diem. Colonel Diem took command of the division on 31 October but could make no noticeable headway in solving the Division's tactical and morale problems. These were too much the results of conditions beyond the control of the commander: an extended front under continuous enemy pressure, the debilitating effects of cold, wet, typhoon weather; inadequate supply to the forward infantry outposts; and the worsening economic straits in which the soldiers found themselves.:61
On 25 July, General Trng ordered the 54th Regiment from Thua Thien to Quang Nam Province for attachment to the 3rd Division fighting the Battle of Duc Duc. The 54th Regiment arrived in Quang Nam on 26 July, put its headquarters at ?i?n Bàn District Town, and immediately went into action. While the 1st Battalion took over a security mission in the Da Nang rocket belt near Hill 55, the 2nd and 3rd Battalions began clearing the area around Ky Chau Village on Go Noi Island. Both the 2nd and 3rd met heavy resistance and proceeded westward slowly, engaging a PAVN/VC force on 28 July and dispersing it with heavy losses.:117 The Regiment returned to Thua Thien in September.:129-30
From 28 August to 10 December 1974 the 3rd and 51st Regiments together with the 15th Ranger Group fought the Battle of Phú L?c forcing the PAVN back from hills overlooking Highway 1 and from which they could shell Phu Bai Air Base. The fighting here and at Thng c weakened the Division and depleted the I Corps reserve forces.:125-31
By making timely and appropriate economy of force deployments, often accepting significant risks, General Trng was able to hold the PAVN main force at bay around Hu?. But the ring was closing on the Imperial City. Reinforced PAVN battalions equipped with new weapons, ranks filling with fresh replacements from the north-were in close contact with ARVN outposts the length of the front. Behind these battalions, new formations of tanks were being assembled and large logistical installations were being constructed, heavily protected by antiaircraft and supplied by newly improved roads.:131
On the early morning of 8 March regiments of the PAVN 324B Division began the Thua Thien campaign attacking along an 8km sector southeast of Hu?. Supported by intense artillery concentrations, PAVN infantry swarmed over the surrounding hills. The 2nd Battalion, 1st Regiment, held on Hill 121, but the 1st Battalion, 1st Regiment, was shattered and driven from Hill 224. The 2nd Battalion, 54th Regiment, was initially forced to give ground but recovered its positions on Hill 144 on 9 March. The Hac Bao Reconnaissance Company was forced from Hill 50 southwest of Nui Bong. Brig. Gen. Diem reacted by dispatching the 15th Ranger Group with the 61st and 94th Ranger Battalions to reinforce the line and recover lost positions. The 61st was ambushed en route, sustained moderate losses, but recovered to join the 94th in a counterattack on 10 March. The next day a prisoner of war confirmed that the PAVN 325th Division had moved south and was in position to join the attack in Phú L?c District.:155
A battalion of the PAVN 6th Regiment infiltrated through Phú L?c, and two of its companies seized 12 fishing boats, which ferried them across Dam Cau Hai Bay to Vinh Loc Island. There they attacked Vinh Hien Village on the southern tip of the island and swept north to attack Vinh Giang. Some of the battalion pushed into Phu Thu District east of Hu?. The 8th Airborne Battalion, reinforced with two companies of the 1st Battalion, 54th Regiment and a troop of armored cavalry, moved against the PAVN battalion and badly mauled and dispersed it. On 16 March a unit of the 54th Regiment ambushed a remnant of the battalion south of Hu?, killing the battalion commander, his staff, and 20 men. Five prisoners taken by the 54th Infantry said that the population gave them no support, and only 33 men, mostly wounded, remained alive in their battalion.:155
On 13 March two battalions of the 3rd Regiment were forced from the Firebase Bastogne area but regained most of their positions in a counterattack the following day.:157
On 14 March, General Trng met with General Thi, commanding I Corps troops in Qu?ng Tr? and Thua Thien Provinces, and General Lan, the Marine Division commander, to explain his concept for the final defense of Da Nang. He would pull all combat forces into Quang Nam and defend Da Nang with the 1st, 3rd and Marine Divisions on line and the 2nd Division in reserve, but this deployment would be approached gradually as divisional troops were relieved in Quang Tri and Thua Thien Provinces and terrain in the southern part of the region was abandoned. Generals Trng and Thi anticipated a mass civilian exodus from Qu?ng Tr? as soon as the people saw that the Marines were leaving, and he directed his staff to prepare plans to assist the refugees.:157
On 19 March at meetings in Saigon with President Thi?u General Trng was directed to stop the evacuation of Hue and to defend enclaves at Hu?, Da Nang, Chu Lai and Quang Ngai City. He could, when forced, surrender Chu Lai and Quang Ngai, but he was to defend Hu? and Da Nang at all costs. When General Truong returned to his headquarters on 20 March, he turned around the displacing 175mm. batteries moving to Da Nang and stopped the evacuation of ammunition from Hu?. The Imperial City would be defended despite the fact that PAVN artillery had, on 19 March, already struck inside the Citadel and Highway 1 was clogged with the southbound traffic of thousands of refugees. The contracted organization for the defense of Hu?, under the command of General Thi, was divided between the deputy commander of the Marine Division, Col. Tri, who was responsible north of Hue, and the 1st Division commander. Brig. Gen. Nguyen Van Diem, south of the city. Colonel Tri's outposts were just inside the Thua Thien-Quang Tri boundary, nearly 30km northwest of Hu?. Here, under the direct command of the 14th Ranger Group, were the 77th Ranger Battalion, seven RF battalions, and a troop of armored personnel carriers of the 17th Armored Cavalry Squadron. The four Marine battalions of the 147th Brigade were in the vital Bo Corridor, within light artillery range of the Citadel, while the 78th and 79th Ranger Battalions were on outposts 10km west of the Marines. South of the Marines, on the high ground at Fire Support Base Lion (also called Nui Gio) (:158-9) was the 51st Regiment, with two of its battalions. General Diem's responsibility began southwest of his 51st Regiment, which was attached to Colonel Tri's command. The 3rd Regiment, with two battalions, held the high ground around Firebase Birmingham, above the Song Huu Trach, south of Hu?. East of the 3rd Regiment, the 54th Regiment with two of its battalions defended the Mo Tau sector, while the reinforced 1st Regiment extended the line southeast to the Nui Bong area. The 1st Regiment had, in addition to its own three battalions, one battalion of the 51st Regiment, a company of M48 tanks and a troop of armored personnel carriers. The 15th Ranger Group, with its three battalions and one battalion of the 3rd Regiment, dug in on the hills above Highway 1 west of Phú L?c District Town. The 258th Marine Brigade, with two battalions, was also near Phú L?c, while the 914th RF Group of three battalions guarded the H?i Vân Pass.
On the morning of 21 March the lead battalions of the PAVN 324B and 325th Divisions, together with the independent Tri-Thien Regiment, with heavy artillery support, assaulted South Vietnamese positions from the Bo Corridor to Phú L?c. The attacks against the Marines in the Bo Valley were repulsed with heavy PAVN losses, but the Phú L?c sector, taking the brunt of the attack, began to crumble. In the area of the 1st Regiment, the PAVN 18th Regiment, 325th Division, supported by the 98th Artillery Regiment, took Hill 350 and drove on to assault Nui Bong. Although the mountain changed hands three times that afternoon, the 2nd Battalion, 1st Regiment, controlled it on 22 March. Other formations of the 325th, notably the 101st Regiment, forced the 60th Ranger Battalion, 15th Group, from Hill 500 west of Phú L?c, and supporting artillery interdicted Highway 1. A stream of refugees began piling up along the road northwest of Phú L?c. By evening, however, one lane was opened for traffic to Da Nang. To the west, in the hills around Mo Tau, the 27tst Independent Regiment and the 29th Regiment of the 304th Division, both operating under the 324th Division, attacked the 54th Regiment and were repelled. A prisoner from the 27lst said that casualties in his regiment were very heavy, that the 9th Battalion was nearly destroyed. PAVN attacks continued all along the Thua Thien front on 22 March. An ARVN counterattack to recapture Hill 224, a key position in the Mo Tau sector, failed. The population of Hu? had declined to only 50,000, and the H?i Vân Pass was clogged with desperate people trying to escape.:159
On 23 March the 913th Regional Forces Group on the My Chanh Line north of Hu? withdrew without orders and they refused to stop at the next delaying position near Phong Dien District Town. The 913th's pullout caused some panic among other forces and a general rout developed. I Corps officers attempted to rally the troops at the Bo River. The mass desertion was not motivated by fear of the PAVN but by the soldiers' overwhelming concern for the safety of their families in Hu?. On 24 March, after receiving the report of the collapse of the My Chanh line, General Trng met with his commanders, General Thi, Maj. Gen. Lan, Maj. Gen. Hoang Van Lac (deputy commander of I Corps) and 1st Air Division commander, Brig. Gen. Nguyen Duc Khanh. General Lac reported that Da Nang was close to panic also, with more than 300,000 refugees jamming the streets. At 18:00 on 24 March. General Trng ordered General Thi to begin the evacuation of all troops defending Hu?. All forces north and west of Hu? would assemble at Tân M? Base, the port of Hu? northeast of the city, cross the narrow channel to Phu Thuan and march southwest down Vinh Loc Island. Crossing the mouth of Dam Cau Hai Bay on a pontoon bridge to be constructed by ARVN engineers and moving along the beach to Highway 1, they would cross over the H?i Vân Pass and on to Da Nang. No trucks, tanks, or guns could make this march; all would have to be disabled or destroyed. The Division would protect the column by blocking in Phu Thu District. By the time these orders were issued, what was left of the population of Hue was streaming toward Tân M? Base to take any available boat or ship out of Thua Thien Province. I Corps Forward commanded by General Thi, established its command post in Tân M?, together with the command posts of the Marine Division and the 147th Marine Brigade. The 7th Marine Battalion deployed there to secure the port and the command posts. The Division withdrew from the Troui-Nui Bong sector. The 15th Ranger Group, which had held the Troui River for the pulled back to Phu Bai Combat Base with heavy casualties. The 54th Regiment withdrew from the Mo Tau sector to Camp Eagle, southeast of Hu? near Highway 1. The 3rd Regiment withdrew from its forward positions on the Son Hue Trach and assembled in Nam Hoa, south of Hu?. The 51st Regiment pulled back and located just west of the city while the division headquarters and the 1st Regiment, which had suffered moderate casualties in the Nui Bong sector, were around Hu?.:160
The withdrawal from Thua Thien Province began in a rather orderly fashion. The 258th Marine Brigade linked up with the 914th RF Group on Vinh Loc Island to cross the narrow channel over to Loc Tri in Phú L?c District, but the bridge to be installed by ARVN engineers never got there; engineer boats were evidently commandeered by other military units attempting to escape. The withdrawing forces crossed anyway, using local fishing boats. General Trng flew over the column making its way down the long stretch of Vinh Loc Island and noted that the only apparent disciplined, cohesive units were marines. The rest was a mob and the Division ceased to exist as an identifiable unit, most Division soldiers who escaped from Hu? were subsequently captured at Da Nang; no attempt was made to reconstitute the Division.:161