Rescuers were continuing to search for one missing worker at the Clairton Coke Works more than five hours after mid-morning explosions rocked the Mon Valley plant. The blasts killed one person and injured 10.

Two people were killed and 10 others were injured in an explosion at the U.S. Steel Clairton Coke Works plant on Monday.

An explosion at a U.S. Steel plant south of Pittsburgh killed two people and injured more than 10 others. The CEO has vowed to find out what caused Monday’s blast while the workers’ union says it will make sure there’s a thorough investigation.