Northampton Area School District students were stranded Friday after school when their driver left the bus in mid-route, the superintendent said. There was “some type of disturbance” on Bus No. 21 before the driver pulled into a Sunoco at Routes 512 and 248 around 3:10 p.m., said Superintendent Joseph Kovalchik, who added that he wasn’t sure exactly what had happened. “The kids are all safe,” he stressed.