Workers were pushing coke out of huge ovens and preparing for maintenance when an explosion rocked a US Steel plant outside Pittsburgh, a company executive said Tuesday, a day after the blast killed two workers.

One person has died and dozens are reportedly injured or trapped under rubble following an explosion at a U.S. Steel plant near Pittsburgh on Monday, an Allegheny County emergency services spokesperson told the Associated Press.

A deadly explosion rocked the U.S. Steel Clairton Coke Works plant late Tuesday morning, leaving one worker dead, one still unaccounted for, and multiple others injured. The blast was reported at 10:51 a.