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.

By the time the scene was secure, two people were dead and more than 10 others were injured, including one who spent hours trapped in rubble left Monday by the blast that was powerful enough to shake nearby homes.

At least one person has died, and one person remains unaccounted for, while at least 10 people have been injured following multiple explosions at the U.S. Steel Clairton plant.