ERIE, Pa. (AP) – A coke plant in northwestern Pennsylvania has shut down. Erie Coke turned away employees who showed up for work Thursday morning. The company has faced mounting regulatory pressure over its environmental record. The city of Erie had recently forced Erie Coke to halt the discharge of wastewater into the municipal sewer system. That came after Pennsylvania environmental officials denied the renewal of the company’s operating permit and took legal action to get the plant shutdown, citing years of environmental violations. Erie Coke employed more than 130 people at the plant, which produces a key ingredient in the steelmaking process.