Detroit City, aka Coelman Young, Airport has been subsidized by the city, to the tune of over $1M/year. This year, the airport received a $100M grant from the FAA to improve facilities.
There is a general aviation airport a block from my home. It used to be privately owned, but, the owners got tired of losing money on it. Someone with a lot of juice wants that little airport kept open, rather than moving their plane to Willow Run, so the Michigan Dept of Transportation now owns it, and runs it at a loss, for the benefit of that big shot.