Authorities are continuing an investigation into a fire that damaged the Cascade Plastics plant in Truesdale Monday evening, March 8. A cause of the fire has not been determined, according to Warrenton Fire Chief Mike Owenby. The state's fire marshal office was at the scene conducting the investigation along with the Bureau of Alcohol, Tobacco, Firearms and Explosives due to the size of the large facility. The Cascade Plastics plant is located at 7501 South Spoede Lane in the Daniel Boone Area Industrial Park. The company, headquartered in Canada, manufactures polystyrene foam trays. The plant, which was closed Tuesday, opened in 2000. The fire was first reported around 11 p.m. when 911 dispatch was contacted by the alarm company. Several calls from employees were made as well, Owenby said. He reported the fire was contained to the middle section of the building and was extinguished by the building's sprinkler system. Firefighters spent most of the early morning ventilating the facility. All employees working at the time evacuated safely. "The sprinkler system did its job," Owenby said. Firefighters had to use caution when entering the building due to the nature of the materials inside. "It's a high hazardous building for us," Owenby said. Other fire departments responding to the scene included Wright City, Wentzville, Marthasville and Hawk Point. Coincidentally, Warrenton firefighters responded to the plant around 10:30 p.m. on Sunday evening for a small fire. Employees extinguished the flames prior to crews arriving. Owenby said the fire was located in the front storage area of the building where the foam trays are packaged and prepared for shipping. Owenby said it was believed at that time the fire was caused by a malfunctioning light fixture, although an official cause has not been made. Crews were on the scene Sunday evening for about an hour.