Preparations for a routine maintenance task may have led to an explosion at a U.S. Steel coal-processing plant near Pittsburgh that left two dead and sent 10 to hospitals, the company said Friday. U.S.

Two workers died and at least 10 people were injured after multiple explosions at the U.S. Steel Clairton plant.

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.