 European cities including London and Paris had laws to ban tall buildings, but elsewhere skyscrapers began to appear, including Toronto's Imperial Bank of Commerce Building, Antwerp's Boerentoren and Buenos Aires' Kavanagh, Comega and Safico buildings.Many other European skyscrapers were proposed in a frenzy of excited planning, although few materialised.Soviet Russia began the construction of the Palace of the Soviets in the late 1930s, in the Socialist Classicism style, which would have become the tallest building in the world, but war intervened and the skyscraper was never completed.