Police: Plant shooter kills 5 co-workers, then self

(CNN) -- Police said a worker at a plastics plant in Henderson, Kentucky, shot and killed five co-workers and then himself after an argument with a supervisor Wednesday.

The worker "had words with a supervisor" before going on a half-hour break Tuesday night, Henderson police Sgt. John Nevels said.

"He came back," Nevels said. "Witnesses saw the supervisor and the shooter walk outside together. They heard a gunshot, and the shooter come back inside the plant, and he shot numerous people."

Two people died at the scene, and four others died at hospitals in Henderson and nearby Evansville, Indiana, said Janet Campbell of the Henderson Police Department.

Another victim is hospitalized and is expected to survive, she said.

It is unclear whether the supervisor was among those killed. Watch authorities respond to the scene »

About 35 people were inside the Atlantis Molded Plastics Inc. plant working the overnight shift when the shooting happened, Nevels said.

Investigators were interviewing witnesses to determine the motive of the shooting and the identity of the victims, another police officer said.

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