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.

A man who called authorities frantically described the violent scene early Wednesday to a dispatcher, tallying up the number of dead around him.

"There's more than two people dead. There's like one, two, three, four, five people dead," the man said. "The supervisor is dead, too."

Authorities said Higdon was known to keep a .45-caliber pistol in his car, which is not illegal in Kentucky.

Ventura said she was not aware that Higdon carried a gun in his car, the newspaper said. She described him as generous and "a good person." Ventura has a 7-month-old son with Higdon, the newspaper said.

The first shooting took place as the supervisor was escorting Higdon from the building. Other co-workers were shot in the break room and on the plant floor. One worker was injured and was being treated in the critical care unit at St. Mary's Hospital and Medical Center in Evansville, Indiana.

"He just walked in, looked like he meant business and started shooting at everybody," Henderson Police Sgt. John Nevels said at a news conference.

The facility closed for most of the day but reopened for limited production Wednesday night, plant manager Dean Jorgensen said Thursday.

The killings stunned the Ohio River town of about 28,000 people, where a local leader said many residents know or are related to a worker at the plant. The plant, operated by Atlanta-based Atlantis plastics, employs about 160 people and makes parts for refrigerators and plastic siding for homes.

Henderson County Coroner Bruce Farmer identified the supervisor as Kevin G. Taylor, 30. The slain co-workers were Trisha Mirelez, 25; Rachael Vasquez, 26; Joshua Hinojosa, 28; and Israel Monroy, 29. The hospitalized survivor was identified as Monroy's sister, Noelia Monroy.

Noelia Monroy was listed in good condition on Thursday, hospital spokeswoman Cheryl Dauble said.

"Our whole community is in shock," Henderson County Judge-Executive Sandy Watkins said.

A prayer vigil was held for the victims Wednesday night at the Henderson County Courthouse.