Officials in Henderson, Kentucky say a sixth person has died from injuries suffered in a workplace shooting early today.The incident occurred at the Atlantis Plastics plant, where police say an employee opened fire after an argument with his supervisor. Five people died at the scene, including the gunman, who took his own life. A sixth person died later at a hospital in Evansville, Indiana. Another victim is being treated at the hospital.The names of the victims and the gunman have not been released.