Tong Le Chon camp -- also called Tonle Cham -- sat beside the Saigon River on Route 248, eight kilometers southeast of the Cambodian Fishhook and roughly 14 kilometers southwest of An Loc. First established in 1967 to monitor North Vietnamese infiltration from base areas across the border, the camp occupied a strategically inconvenient position. The ARVN presence forced the People's Army of Vietnam to detour around its preferred supply corridors running from Tay Ninh Province into Binh Long Province and south along the Saigon River toward Binh Duong Province. After the Battle of An Loc, the ARVN 18th Division handed the area's defense to the III Corps Ranger Command, and the 92nd Ranger Battalion drew responsibility for Tong Le Chon. It was a posting that demanded endurance. The camp was isolated, resupply was difficult even in peacetime, and the surrounding jungle belonged to the enemy.

The North Vietnamese siege began on March 25, 1973 -- two months after the Paris Peace Accords were supposed to have ended the fighting. The bombardment was almost continuous. In the first 16 weeks alone, the PAVN launched nearly 300 fire attacks, pouring more than 13,000 mortar, rocket, and artillery rounds into the camp. There were 11 ground assaults and at least 9 sapper infiltration attempts. Between the barrages, loudspeakers promised the Rangers safe passage if they surrendered. They did not. By early July, the 92nd had been reduced to 224 officers and men, of whom 34 were out of action from wounds, beriberi, or malaria. They had counted 86 enemy dead and captured 10 weapons, including an antiaircraft machine gun. The Republic of Vietnam Air Force flew over 3,000 sorties to keep the camp alive, dropping more than 300 bundles of food and supplies by parachute. The defenders recovered only 134 of them. The rest fell into North Vietnamese hands.

Helicopter resupply became nearly suicidal. Antiaircraft positions thickened around the camp as units from the 42nd and 271st Antiaircraft Regiments, equipped with 37-millimeter and 57-millimeter guns, ringed the approaches. Between late October 1973 and January 1974, twenty helicopters attempted to land at Tong Le Chon. Only six managed it, and three of those were destroyed on the ground. In December alone, 13 helicopters were hit by enemy fire on Tong Le Chon missions. A defecting PAVN platoon leader later offered a remarkable detail: the North Vietnamese had organized a dedicated company to collect parachuted supplies that drifted outside the camp perimeter. He claimed an informal understanding existed between the Rangers and the PAVN -- C-130 transport planes dropping supplies would not be fired upon, so long as the Rangers did not oppose the collection of bundles that fell outside their wire. The claim was never confirmed, but it fit the strange, desperate logic of life at Tong Le Chon, where survival depended on tacit calculations between enemies.

By March 1974, the 92nd Rangers' situation was untenable. Seriously wounded soldiers could be neither treated nor evacuated. Resupply came only by parachute. Lieutenant General Pham Quoc Thuan proposed three options to the Joint General Staff chief, General Cao Van Vien: launch a division-sized relief operation from An Loc, negotiate the Rangers' withdrawal with the PAVN, or order the 92nd to exfiltrate in small groups. Everyone knew only the third option was remotely feasible. The ARVN could not punch through to Tong Le Chon when it could not even secure the road a few miles north of Lai Khe, and all divisions were already committed elsewhere. The decision was referred to President Nguyen Van Thieu, who said nothing. Meanwhile, Colonel Ngon's messages grew more desperate. He asked for more airstrikes, knowing they could not change the outcome. He asked for a ground relief column, knowing it would never arrive. In what he described as the only alternative to surrender, he asked for airstrikes on his own camp. His men, he said, would never give up.

The order to hold at all costs came at 23:30 on April 11. Colonel Ngon ignored it. After midnight his Rangers burned their documents, destroyed equipment, and began moving northeast through the jungle toward An Loc, 16 kilometers away through PAVN lines. Fourteen more men were wounded during the night's final bombardment. Thirty-five more fell during the withdrawal itself. Every wounded soldier was brought out. Those who could not walk were carried. Four Rangers were killed in firefights along the route, and even their bodies were carried to An Loc. By April 15, the last survivors entered the An Loc perimeter. When the PAVN finally overran the empty camp on April 13, they found all equipment destroyed, all wounded evacuated. Only two Ranger bodies and a single captured Ranger were left behind. A captured PAVN soldier revealed that North Vietnamese infantry had been ordered to block the withdrawal but had refused, fearing the South Vietnamese air and artillery fire covering the escape. Colonel Ngon was not punished for his disobedience, but the 92nd Ranger Battalion was quietly dissolved and its men kept from the press. With Tong Le Chon gone, the PAVN had unrestricted control of the east-west corridor between Tay Ninh and Binh Long.