In the beginning of the 1950’s, the factories started to be moved to the periphery of Detroit. The middle class started to leave downtown and move to the suburbs. Industrialization began to decline, the segregation of the population became more pronounced. In 1967, social tensions resulted in the strongest urban riot in American history. People began to leave the city en masse, leaving the whole city districts empty. Old buildings in downtown were deserted, and within 50 years, Detroit has lost more half of its population.