were in disrepair. Pre-famine shocks and distress Throughout 1942 and early 1943, military and political events combined with natural disasters and plant disease to place widespread stress on Bengal's economy. While Bengal's food needs rose from increased military presence and an influx of refugees from Burma, its ability to obtain rice and other grains was restricted by inter-provincial trade barriers. Japanese invasion of Burma The Japanese campaign for Burma set off an exodus of more than half of the one million Indians from Burma for India. The flow began after the bombing of Rangoon (1941–1942), and for months thereafter desperate people poured across the borders, escaping into India through Bengal and Assam. On 26 April 1942, all Allied forces were ordered to retreat from Burma into India. Military transport and other supplies were dedicated to military use, and unavailable for use by the refugees. By mid May 1942, the monsoon rains became heavy in the Manipur hills, further inhibiting civilian movement. The number of refugees who successfully reached India totalled at least 500,000; tens of thousands died along the way. In later months, 70 to 80% of these refugees were afflicted with diseases such as dysentery, smallpox, malaria, or cholera, with 30% "desperately so". The influx of refugees created several conditions that may have contributed to the famine. Their arrival created an increased demand for food, clothing and medical aid, further straining the resources of the province. The poor hygienic conditions of their forced journey sparked official fears of a public health risk due to epidemics caused by social disruption. Finally, their distraught state after their struggles bred foreboding, uncertainty, and panic amongst the populace of Bengal; this aggravated panic buying and hoarding that may have contributed to the onset of the famine. By April 1942, Japanese warships and aircraft had sunk approximately 100,000 tons of merchant shipping in the Bay of Bengal. According to General Archibald Wavell, Commander-in-Chief of the army in India, both the War Office in London and the commander of the British Eastern Fleet acknowledged that the fleet was powerless to mount serious opposition to Japanese naval attacks on Ceylon, southern or eastern India, or on shipping in the Bay of Bengal. For decades, rail transport had been integral to successful efforts by the Raj to forestall famine in India. However, Japanese raids put additional strain on railways, which also endured flooding in the Brahmaputra, a