A man whom the U.S. described as a key figure in Al Qaeda in the Arabian Peninsula accidentally blew himself up, U.S. military officials told Fox News. The officials say Nayif Al-Qahtani was "messing with a bomb" when it went off. U.S. officials had been watching him, but Fox News' sources insist the U.S. had nothing to do with his death. Al-Qahtani was "a vibrant guy linked to ongoing operations planning, and his death will have an impact," one official told Fox News. An Al Qaeda in the Arabian Peninsula newsletter was the first to announce his death a week...