Preparations for a routine maintenance task may have led to an explosion at a U.S. Steel coal-processing plant near Pittsburgh that left two dead and sent 10 to hospitals, the company said Friday. U.S.

• At least one person is dead, 10 injured and one unaccounted for in an explosion at the Clairton Coke Works in Pittsburgh, Pennsylvania. The cause of the explosion is unknown and officials are investigating, US Steel said.

A devoted dad has been identified as one of the two steel workers killed from an explosion at a Pennsylvania steel plant on Monday, officials said.

Workers were heating coal and preparing for routine maintenance when an explosion rocked a U.S. Steel plant outside Pittsburgh

The mill, which is part of the recent merger between U.S. Steel and Nippon Steel, has faced scrutiny from federal and local regulators.

U.S. Steel has released new details on what investigators believe caused the explosion at the Clairton Coke Works plant that killed 2 people and injured 10 others.

The Pennsylvania county where an explosion at a U.S. Steel plant south of Pittsburgh killed two people and injured more than 10 others announced Thursday that it is stepping up air quality monitoring in the area of the sprawling facility that has a troubled environmental record.

“It is with profound sadness that I share with you that the U. S. Steel colleague who had been unaccounted for has been located and confirmed deceased, following an extensive search and rescue effort," David Burritt, the company's CEO, said in a statement. At least 10 people were injured in the blast, officials said.

Family members tell Pittsburgh's Action News 4 Steven Menefee, a father of two, was a loving man who would give you the shirt off his back.