I don't think the possibility of the Big One precludes too many skyscrapers from being built. Skyscraper building techniques are such that this is of minor conc

I don't think the possibility of the Big One precludes too many skyscrapers from being built. Skyscraper building techniques are such that this is of minor concern and the large skyscrapers would most likely fair better than most older, shorter buildings these days.