A Newtown Police detective hit a school bus yesterday afternoon.  The incident happened near the police station as the cruiser pulled out of the Main Street parking lot and bumped the rear of the loaded bus, just north of the lot.  Police say there were no injuries reported.  The detective in an unmarked Chevy Impala was not headed to a call at the time.  Officers with the traffic unit are conducting the investigation, including noting the names of the students and where they were sitting on the bus.  The schools contacted parents to alert them to the incident.