An explosion occurred Monday at a steel factory in Clairton, Pennsylvania, authorities said. A spokesperson for Allegheny County said a rescue operation was underway at U.S. Steel Clairton Coke Works for people trapped under the rubble.

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.

An explosion at a U.S. Steel plant near Pittsburgh left two dead and sent at least 10 to hospitals Monday and heavily damaged the sprawling facility, officials said.