boys were abducted on their way to school exams. some said they were beaten with electric cables because they're from a religious minority. this year, isis seemed to come out of nowhere as it grabbed about a third of iraq and syria but where did isis start? clarissa ward traced roots back to a u.s. military prison. >> camp bucca was one of the largest and toughest prisons in iraq. as insurgency raged, buccas numbers swelled. there is growing evidence that the sprawling prison was the birth place of isis. ngcording to a "cbs news" investigation at least 12 of the top leaders of isis served time at camp bucca including the man who would be the group leader abu bakr al baghdadi.