U.S. Steel says its preliminary investigation found that the blast happened after pressure built up while a gas valve was ...

Allegheny County is increasing air quality monitoring after an explosion at a U.S. Steel plant south of Pittsburgh killed two ...

Preparations for a routine maintenance task may have led to an explosion at a U.S. Steel coal-processing plant near ...

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

An explosion at a steel plant in Pennsylvania on Monday has led to an extremely serious situation. The explosion at the plant ...

HARRISBURG, Pa. (AP) — The fatal explosion last week at U.S. Steel’s Pittsburgh-area coal-processing plant has revived debate ...

Authorities said their investigation has shifted to the cause of the explosion after they accounted for everyone who was missing.

The plant, a massive industrial facility along the Monongahela River south of Pittsburgh, is considered the largest coking ...