BETHLEHEM, Pa. — Authorities say a train derailment in eastern Pennsylvania has left some railroad cars along a riverbank Saturday morning and at least one partially in the river itself.Dispatchers in Northampton County said the derailment was reported at 7:14 a.m. in Lower Saucon Township. Authorities said it was unclear how many cars were involved but no injuries or hazardous materials were reported.The Nancy Run Fire Company posted pictures showing a number of railroad cars scattered…