AUBURN — Firefighters spent more than an hour checking duct work at Pioneer Plastics for flames Sunday evening after the company’s dust collection system caught fire.

Battalion Chief Scott Hunter of the Auburn Fire Department said that about 13 firefighters responded to the Pionite Road plastics plant at about 6:34 p.m. Sunday. He said a dust collection system overheating or bad bearing is believed to be the cause of a small fire on the roof of the building.

Hunter said that crews cleared the scene shortly before 7 p.m. after finding three other small fires in the duct work during a check of the plant’s system following the initial fire.