Shell Oil Co. announced it will build a massive petrochemical "cracker" plant in Potter, Pennsylvania, making it the winner in a tri-state competition for the billion-dollar industrial operation. Ohio Gov. John Kasich lobbied hard for the plant, as did leaders in West Virginia. The Thursday decision caps a months-long courting by state and national officials for the plant, which promises thousands of jobs and is expected to bring billions of dollars in investment to the region. The cracker plant will break down gas compounds extracted from the Marcellus Shale into other elements, including propane.