There have always been cyclical boom and bust towns, like Houston and Calgary; booming when oil is in demand and busting when over capacity and low prices reign.
But there are some boom and bust towns that take a decade or two to recover from the excesses of doing too much of the same thing. In modern times, Seattle and Detroit come to mind.
Back in the early 1970s, when Bill Gates was in junior high school, Seattle's main employer was the Boeing Company. Boeing had lost the super military transport contract to Lockheed, the supersonic transport development had ended and commercial carriers were waiting for the jumbo 747 to be built. Unemployment became extremely high in this one-industry town and banks were pleading with people to stay in their houses when they couldn't make their mortgage payments. In late 1972 when I left Seattle, there was a billboard at the edge of town asking the last person leaving to "turn off the lights." It would be a couple of decades before Gates and Company transformed Seattle into an information technology center; ending sole dependence on Boeing to supply the area's jobs.
Here in the Metro Detroit Area where 1 in 5 of the country's engineers live, the automotive industry bubble is just starting to burst. Over production capacity, the global economy, high gasoline costs and a product line of large SUVs have combined to put General Motors (GM) and Ford (along with their supply chains) into a negative cash flow spiral.
Like Seattle, expect a decade or two for an economic turnaround to happen in Detroit based on the future entrepreneurship of a few junior high school students of today. That is why educating kids well today can have a positive economic impact on future generations.