met by ARVN artillery losing 30 dead and one T-54 tank destroyed before they pulled back. On 28 April the 341st renewed their attack using 5 T-54s supported by an infantry regiment, but were repulsed in 3 separate attacks losing 3 T-54s and many soldiers. On 29 April the entire 341st Division attacked Hố Nai and were again repulsed in 2 hours of fighting. At midday the Marines were ordered to withdraw to defend Bien Hoa and Long Binh. Brigadier General Trần Quang Khôi, commander of the 3rd Armored was given responsibility for defending Bien Hoa, although PAVN shelling had rendered the base unusable. Seeing the regular forces leaving Hố Nai the PAVN renewed their assault at midnight on 30 April, but the town's Popular Forces fought back and were not subdued until dawn. The PAVN then advanced to Bien Hoa where they were met by the 3rd Armored, at this point the PAVN 4th Corps changed the axis of their advance to the south. On the morning of 30 April the 18th Division and Marines were ordered to retreat from Long Binh to the west bank of the Đồng Nai river, while the ARVN 81st Rangers held Bien Hoa Air Base and the 3rd Armored held Bien Hoa. The 3rd Armored was moving from Bien Hoa to attack PAVN forces when they heard the surrender broadcast of President Dương Văn Minh and BG Khôi halted his advance and disbanded the unit. The 81st Rangers had abandoned the base and had moved west of the Đồng Nai river when they heard the surrender broadcast and then marched towards Saigon to surrender to the PAVN. VPAF use The VPAF 935th Fighter Regiment equipped with Sukhoi Su-30MK2 is based at Bien Hoa. In April 2019 it was announced that the United States Agency for International Development was beginning a 10-year US$183 million project to decontaminate the base of Dioxin caused by Agent Orange defoliant stored at the base during the Vietnam War. The base was described as the most contaminated site in Vietnam and Dioxin had contaminated the soil and waterways. Accidents and incidents In March 1966 a C-123 of the 311th Air Commando Squadron carrying 6 tons of artillery shells was hit by ground fire while climbing from the base, starting a fire in the left engine, it turned back and made an emergency landing and was destroyed by fire after