I really can't add to that in any meaningful way. There is one little angle to the Braddock story that gets lost. These days most consider population loss in Braddock the result of industry decline which isn't really the core. If you look longer term at the numbers, Braddock's population loss was well entrenched while the local Steel industry was doing well. Local workers were able to move out into newer suburbs as their wages went up and did so long before the 1980's. I'd say the bulk were long gone from Braddock itself by the time the steel related job losses accelerated. It just highlights how difficult the problems in Braddock are being both an inner suburb losing population to further suburbs, and being at the center of the steel industry's implosion. It's an important point to understand Braddock's future as well as it's past.
But whatever the causes, the factoids about population loss in Braddock are stark and true. Braddock's population was once over 20K, by 1980 its population was already under 6K (so over 70% of the population loss came before the real implosion of steel employment in the 1980s's) and today is to be under 2,700. Not many places in the US have had demographic demontage on that scale.