Chunks of concrete dangle from exposed floors of a half-demolished warehouse next to the Sixteenth Street Bridge.

No one will miss this ugly building—or at least no one will admit to missing it. But it does point out a principle that old Pa Pitt has often stated: prosperity is more destructive to old landmarks than any other force except possibly war—and even then it depends on the war. When the city is prosperous, there is a strong incentive to replace older things with newer, more profitable things. Fortunately Pittsburgh has learned a lot about appreciating its old buildings, and much of what is going on in the booming Strip District is restoration and adaptation rather than demolition. But old buildings are in much more danger when the city is prosperous than when the local economy is stagnant.