sentences:  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.