Our enemy was ingenious using our trash against us. Rockets aimed at Fire Support Base Washington were found in the surrounding rice paddies placed on ammo box lumber as a launching/guidance pad. They were launched using discarded D-cell batteries for the electrical spark and our trashed communication wire to carry it. The timer was a C-ration can with the top removed and placed floating in the water-filled can that had a small hole in the bottom. One wire was attached to the lid and the other to the bottom of the can to complete the circuit when the can emptied. The hole in the can let out water and when it was gone the circuit completed and launched the rocket. By then the crew was long gone.