sentences:  The operation rendered the 263rd Battalion combat ineffective.On 4 December 1967 while participating in Operation Coronado IX with the MRF, a flotilla of ATCs carrying the 5th Marine Battalion came under fire 12km east of Mỹ Tho from the VC 502nd Local Force Battalion in a fortified base on the west bank of the Rach Ruong Canal.The VC attacked the boats with rockets and automatic weapons and the Marines were landed north of the VC position and proceeded to overrun the position killing over 100 VC and scattering the rest.