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.

“It is with profound sadness that I share with you that the U. S. Steel colleague who had been unaccounted for has been located and confirmed deceased, following an extensive search and rescue effort," David Burritt, the company's CEO, said in a statement. At least 10 people were injured in the blast, officials said.

An explosion rocked a steel plant outside Pittsburgh on Monday, leaving two dead and 10 others injured, including a person who was rescued from the smoldering rubble after hours of being trapped. The explosion sent black smoke spiraling into the midday sky in the Mon Valley,