U.S. Steel's Clairton Coke Works

Steam billows out of U.S. Steel's Clairton Coke Works on Tuesday, March 5, 2019 in Clairton, Pa. The coke plant has come under scrutiny after a Dec. 24 fire triggered an air quality alert from the release of sulfur dioxide.

Cheryl Hurt stands in her home where she runs a daycare center on Tuesday, March 5, 2019 in Clairton, Pa. Hurt keeps an air monitor in her home to keep an eye on the air quality since the Dec. 24 fire at U.S. Steel's Clairton Coke Works. A lifelong resident of Clairton, Hurt says, "I just want us to be able to breathe."

Steam billows out of U.S. Steel's Clairton Coke Works behind a shuttered business along route PA-837 on Monday, March 4, 2019 in Clairton, Pa. The coke plant has come under scrutiny after a Dec. 24 fire triggered an air quality alert from the release of sulfur dioxide.

U.S. Steel's Clairton Coke Works stands behind homes on Tuesday, March 5, 2019 in Clairton, Pa.

Mia Hamlin, 51, of Clairton, Pa., stands near U.S. Steel's Clairton Coke Works on Tuesday, March 5, 2019 in Clairton, Pa. Hamlin says, "It's just not me I'm concerned about. It's all the residents," speaking of her fear of the air quality in Clairton after a Dec. 24 fire at the plant triggered an air quality alert from the release of sulfur dioxide.

U.S. Steel's Clairton Coke Works stands above homes on Tuesday, March 5, 2019 in Clairton, Pa.

Flames shoot out of the hillside at U.S. SteelÕs Irvin Works in West Mifflin, Pa., where coke oven gas is being flared from U.S. Steel's Clairton Coke Works on Tuesday, March 5, 2019.

Don Elliott, 40, of North Huntingdon, Pa., a gas handling technician and union safety representative at U.S. Steel's Clairton Coke Works, sits in the United Steelworkers Local 1557 union hall on Tuesday, March 5, 2019 in Clairton, Pa.

Don Furko, president of the United Steelworkers Local 1557, which represents workers in the Clairton plant, left, and Don Elliott, a gas handling technician and union safety representative at U.S. Steel's Clairton Coke Works, right, stand in the union hall on Tuesday, March 5, 2019 in Clairton, Pa.

A photograph of President Harry Truman meeting with the mayor of Clairton in 1948 hangs on the walls of the United Steelworkers Local 1557 union hall on Tuesday, March 5, 2019 in Clairton, Pa.

David Palyo, 63, of Glassport, Pa., stands in his home on Tuesday, March 5, 2019 in Glassport, Pa. Palyo is concerned about the air quality in Clairton after a Dec. 24 fire at U.S. Steel's Clairton Coke Works triggered an air quality alert from the release of sulfur dioxide. Glassport sits directly downwind from the plant and across the river from another one of U.S. Steel's plants where coke gas is being flared.

Read more about about this story in the Wall Street Journal.