A worker at a plastics plant in western Kentucky killed five fellow employees Wednesday before turning the handgun on himself, police said, reported dpa.
A sixth victim, a woman, was still alive, Detective Preston Herndon told Deutsche Presse-Agentur dpa.
The shootings took place early Wednesday at the Atlantis Plastics Inc factory in Henderson, Kentucky, possibly triggered by an argument, Herndon said.
Police have not named the shooter pending notification of family.
"We know that sometime during his shift that he and his supervisor became involved in an argument. We're not certain what part that played in the incident," Herndon said.
After the argument, the shooter left on a break and returned with a handgun, opening fire on fellow employees, police said.
The plant produces injection-molded products, according to the Atlanta-based company's Web site. The Ohio River town of Henderson is 127 kilometers east of Louisville. dpa pr