LINCOLN, Neb. (AP) – A former Lincoln Public Schools district worker has pleaded not guilty to starting a fire that destroyed the district headquarters building. Forty-four-year-old Sharon Brewster made her plea Wednesday in Lancaster Country District Court. Brewster remains free on bond. She was arrested on Aug. 15. Prosecutors allege that Brewster set flame to some papers on May 30 on a supervisor’s desk over frustration about how she was being treated. The fire caused an estimated $20 million in damage. If she were convicted of the arson charge, Brewster would face up to 20 years in prison. Her trial has been scheduled to begin on Nov. 7.