Eight workers at a Fond du Lac company were transported to the hospital for treatment of carbon monoxide poisoning. Shortly after 2:30pm Monday Fond du Lac paramedics were called to Quality Packaging at 851 Sullivan Road for a report of a possible carbon monoxide leak with warehouse workers feeling ill. Upon arrival fire crews began to treat several workers who complained of symptoms indicative of carbon monoxide poisoning. Alliant Energy was also on scene and they along with fire crews detected elevated carbon monoxide levels in the warehouse. The building was evacuated and ventilated. FDLFR paramedics evaluated several workers, some refused medical attention and were not transported. However, a total of eight patients were transported to hospitals in Fond du Lac and Waupun. The apparent cause of the leak was narrowed down to a forklift used in the warehouse.