I don't agree with the notion that Seattle/Amazon is equivalent to Detroit/Big 3. Seattle has an economic base that is more diversified than its ever been. In fact, Seattle was a mini-Detroit in the 1970's, when Boeing busted. That inspired policies that brought in service jobs in the tech and bio-tech fields to diversify away from the overwhelmingly resource and aviation-manufacturing based economy that existed until the early 1980's.
Furthermore, as recently as 2008 Seattle has faced major corporate catastrophe. Washington Mutual, at the time, the biggest occupant of office space in the city of Seattle collapsed (the biggest bank failure in US history). Even without the Amazon boom, that office space was would have been fully absorbed by the market by 2012, or something. My point is that Seattle has an extensive history of boom and bust cycles, dating back to the 1896 Klondike Gold Rush.
A little off topic, but the first tower did open yesterday!