Authorities said their investigation has shifted to the cause of the explosion after they accounted for everyone who was missing.

Clairton, Pa. — 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.

“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.