The tragedy has rocked the Mon Valley, and its congresswoman wants answers. Democratic Congresswoman Summer Lee is appreciative of U.S. Steel's efforts to get to the bottom of this, but she said this can never happen again.

Dozens of workers at a steel plant near Pittsburgh are trapped beneath rubble following an explosion, and police have confirmed at least one fatality. The incident unfolded Monday morning at Clairton Coke Works near Pittsburgh in Allegheny County.

A fatal explosion that killed two steelworkers and injured more than 10 shut down four of the 10 coke batteries at U.S. Steel's Clairton Coke Works in Pennsylvania.