An explosion at a plant owned by US Steel, an icon of American industry, has killed 2. What to know

An explosion at a U.S. Steel plant south of Pittsburgh killed two people and injured 10 others. The CEO has vowed to find out what caused Monday's blast while union officials say representatives will work to ensure a thorough investigation.

The plant, Clairton Coke Works, is one of four major plants in Pennsylvania owned by U.S. Steel, an icon of the domestic steel industry and American industrialization for over a century. The plant is in the Mon Valley, a region of the state synonymous with steel.