Many places all over the country grew rapidly during some peak period of economic activity, such as when mines were opened, railroads built, and finally, when factories were built. They were all generally accompanied by significant migration to the boom towns were the jobs were. Some, like Western mining towns, only had a short history that came to an end when the mines were worked out and most of the miners left for the next big find just over the mountain. Others, like the coal mines, lasted for decades but either cheaper coal started coming from somewhere else (at least not from overseas) or the managed to dig all of it up and carry it away. Some such communities hang on by a thread but why should it be surprising if the young people move away looking for better opportunities? That's why people went there to begin with. Although it is in the national interest to keep people employed here, it isn't that particular if the jobs are in one place or another. It is sad when the jobs dry up and people have to move away but it's hardly something new.