FAWN, Pa. (AP) — Authorities say a dispute between two teenage boys on a school bus in western Pennsylvania ended in a street brawl involving a crowbar that left one teen critically injured. The two Highlands School District students, ages 14 and 17, were arguing on the bus Tuesday when the older teen opened the emergency exit and ran out when the bus stopped on a road in Fawn. Authorities say the younger boy followed, grabbing a crowbar that was mounted near the bus driver. The older teen eventually got control of the crowbar and repeatedly hit the younger boy in the stomach and head, causing several skull fractures and other injuries.