Natural disasters, fires, and earthquakes, destroyed Japan's cities in whole or in part on numerous occasions over the last centuries. Human intervention, political change, modernization, and the air raids of the Second World War brought about further destruction and promoted the transformation of the Japanese city in the 19th and 20th centuries. Carola Hein argues that the traditional patchwork character of Japanese cities allowed for flexibility in their transformation, and that many traditional features of Japanese urbanism survived in spite of the obvious changes. The reconstruction of Japanese cities was generally left to private initiative and comprehensive centralized planning intervention, and only occurred when and where the cities had to be adapted to political, economic, social and cultural changes.