Estimates of the deaths directly related to the construction of the Burma railway differ depending upon the source. For the impressed workers from Southeast Asian (romusha), estimates vary widely, although authorities agree that the percentage of deaths among the romuska was much higher than among the foreign prisoners of war. The total number of romusha working on the railroad may have reached 300,000 and the number of deaths among them has been estimated as high as fifty percent.
The lower death rate of the Dutch POWs compared to other POWs is attributed to the fact that many of them had been born in the Dutch East Indies, some with local heritage, and were thus more accustomed to tropical conditions than the British, Australians, and Americans. Officers fared much better than enlisted men; their weight loss during the construction was 20 to 30 pounds less than that of enlisted men. The survival of POWs was also due to luck. Some cohorts of workers, especially those in more isolated areas, suffered a much higher death rate than others.