POW MESSAGE CARD FROM CAMP 4
According to Postal History of American POWS: World War II, Korea, Vietnam by Norman Gruenzner, Camp O'Donnell was the name of POW Camp No. 4. The camp was located on the island of Luzon, just north of the Bataan Peninsula. Although originally built as a comp for the Philippine Army, after the fall of Bataan it became the final stop on the infamous Bataan Death March. On April 13, 1942, the camp, which consisted of Nipa huts, held 10,000 Americans and 50,000 Filipinos. The Americans were transferred to Cabanatuan in May 1942.

CAMP 4 IS ACTUALLY NICHOLS FIELD AT LAS PIÑAS
AND NOT CAMP O'DONNELL