A 25-year-old press operator shot and killed five co-workers and himself at a plastics plant in rural western Kentucky just hours after arguing with his supervisor about not wearing safety goggles and using his cell phone while on the assembly line, police say. Authorities said Wesley N. Higdon was so riled Wednesday by the argument with his supervisor that he called his girlfriend and told her that he wanted to kill his boss. The girlfriend didn't warn anyone, police said, and just two hours later he argued with another co-worker at a gas station near the plant, then returned and shot and killed his supervisor as they walked outside. He went back inside and shot at co-workers in a break room and on the plant floor. But in an interview with a local newspaper, the girlfriend, Teresa Solano Ventura, said through an interpreter that Higdon had threatened to kill himself, not his supervisor. "He said to her that he was going to kill himself," Abby Valasquez told The Gleaner of Henderson, translating for her cousin, who does not speak English well.