Last year, an explosion at U.S. Steel’s Clairton Coke Works outside Pittsburgh killed two U.S. Steel workers and injured 11 others, including contractors. Six months later, workers remain rattled and community concerns about air pollution from the plant are heightened. The blast comes on top of a string of other accidents at the Clairton plant over time as well as a long history of legal battles between U.S. Steel and Allegheny County regulators. Some current and former workers at Clairton Coke Works say poor management and underinvestment have exacerbated air pollution and undermined workplace safety at the plant where operators already have little margin for error. That's according to reporting from Pittsburgh’s Public Source and The Associated Press.