Modernizing auto factories from multiple 6 story monoliths to sprawling complexes became difficult in an area approaching 2 million inhabitants. This and not allowing annexation [[per state constitution) and lack of cohesive or cooperative regionalization [[see Eastside Al's spot-on description above) led to a downward out-of-control spiral we are still unwilling to deal with.

Then there's also the issue of Detroit wanting cheaper steel, which Pittsburgh strained to produce, so it was sourced elsewhere. Another downward out of control global spiral we are still unwilling to deal with. Union bashing in 3..2..1.........