After the battle of Bataan, which Japan won, they took 60,000 Filipinos and 9,000 Americans prisoner. These prisoners flowed into the camp from April to June of 1942. About 1/3 (20,000) of the Filipino prisoners died and 1,500 of the American prisoners died. The deadliest period for Americans was at the end of May during which 40 prisoners died per day.
The prisoners died in such large numbers because: the Japanese soldiers held surrender in contempt, the prisoners came into the camp while already in a poor physical state, many had Malaria, they ate very little, lived in bamboo huts, and slept on the floor without any covering. The Japanese were surprised at how many prisoners they had captured, because they thought only 10,000 soldiers were fighting them, and did not make enough provisions for them
Japan eventually closed the camp, moving all the prisoners to other camps. The camp was recaptured in 1945.