Gas Valve Failure During Routine Maintenance Work May Have Led to Fatal Explosion, US Steel Says

A portion of the Clairton Coke Works, a U.S. Steel plant, in Clairton, Pa., on Aug. 11, 2025. Gene J. Puskar/AP Photo

HARRISBURG, Pa.—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. Steel said it developed the information, along with other investigators, from reviewing video footage and interviewing employees.