In the post-war period there were often food shortages in Soviet cities, and the USSR experienced a major famine from 1946 to 1947. Sparked by a drought and ensuing bad harvest in 1946, it was exacerbated by government policy towards food procurement, including the state's decision to build up stocks and export food internationally rather than distributing it to famine hit areas. Current estimates indicate that between one million and 1.5 million people died from malnutrition or disease as a result. While agricultural production stagnated, Stalin focused on a series of major infrastructure projects, including the construction of hydroelectric plants, canals, and railway lines running to the polar north. Much of this was constructed by prison labour.