Short answers, pulled from the story.
Estimates range from 400,000 to 2 million deaths. Twenty northern provinces reported 380,000 dead from starvation and 20,000 from disease in May 1945. Governor General Jean Decoux estimated about one million deaths in his memoirs, while Ho Chi Minh cited 2 million in his Proclamation of Independence on the 2nd of September 1945.
The famine resulted from a combination of Japanese and French wartime policies, natural disasters, and Allied bombing. Japanese troops forced farmers to grow jute instead of rice, and both Japan and France burned rice as fuel for power stations after US bombing cut off coal. French price controls fixed rice purchases at 1.40 piastres per 10 kilograms even as market rates rose to 60-70 piastres. Droughts, floods, and the catastrophic rainfall of August-September 1944 destroyed northern crops.
The famine occurred in northern Vietnam, then part of French Indochina under Japanese occupation. The deaths were concentrated in the Red River Delta region. Vietnamese corpses were reported throughout the streets of Hanoi, and survivors walked from town to town in search of food.
Japanese forces requisitioned food from farmers to feed their troops, forced farmers to grow jute instead of rice, exported crops to Japan, and hoarded food even as the famine worsened. Diplomat Bui Minh Dung argued that Japanese military efforts and economic policy for the Greater East Asia Co-Prosperity Sphere played a greater role than any other single factor in the famine.
The Viet Minh directed public anger toward the occupation powers and encouraged peasants to seize rice granaries held by the Japanese and French. Japanese reprisals, including physical mutilation of transgressors, intensified popular anger. Through this period, the Viet Minh grew from a guerrilla organization into a mass movement.
The government of Trần Trọng Kim, installed by Japan in March 1945, sent Minister of Supply Nguyen Huu Thi to Saigon to organize rice shipments northward. A General Relief Association led by Nguyen Van To raised 783,403 dong between March and May. Southern relief associations raised an additional 1,677,886 dong in a single month, including funds used to transport 1,592 tons of rice to famine victims.