The explosion, followed by several smaller blasts, could be felt in the nearby community and prompted county officials to warn residents to stay away from the scene so emergency workers could respond.

Don Furko is a mechanical maintenance planner who this week reached his 25th anniversary at the plant. He was working in a different area with the blast took place.

U.S. Steel released preliminary findings about the potential cause of Monday's deadly explosion at U.S. Steel Clairton Coke Works.