Nippon Steel fight points to industry's uncertain future in Pennsylvania

Nippon Steel’s proposed acquisition of United States Steel has been a source of unease in Pittsburgh, where the metal once dominated the economy and still looms large in the collective psyche.

Critics such as the United Steelworkers (USW) see the transaction as the latest threat to come along in a years-long struggle to keep the industry alive after plant closures in 1970s and 1980s battered the American rustbelt.