Cities in the Midwest are facing a doom loop — and without serious changes these midsize cities could quietly slide into oblivion.Getty Images; Alyssa Powell/InsiderWork from home is crushing Midwestern downtownsYou may have heard that America's cities are in trouble. From the "death of downtowns" to the "urban doom loop," the plight of America's superstar metros — and their central business districts in particular — have been a frequent source of concern for economists, politicians, and commentators.