BAGHDAD, Iraq — Insurgents shot down a U.S. military helicopter south of Baghdad, and the two pilots were rescued with minor injuries, the military said Tuesday. The OH-58D Kiowa Attack helicopter was brougt down by ground fire on Monday. After an Apache helicopter rescued the two pilots, a U.S. warplane dropped two 500-pound, laser-guided bombs on the downed craft to destroy it, the military said in a statement. It gave no further details on the location of the crash and said the incident was under investigation.