Prince George's County Police have arrested two juveniles for allegedly making a bomb threat at a Riverdale high school. Police said the threat was called in to Parkdale High School at 10:15 a.m. Thursday. When officers arrived to the school they were approached by two students who said an individual asked where he could find the school principal, and threatened to blow up Parkdale High School if they didn't tell him. Through the course of the investigation, the detectives were able to trace the initial phone call of the bomb threat to one of the students' cell phone, police said....