United States military and intelligence officials are still piecing together what happened early Saturday that sabotaged an attempt to rescue two hostages from al Qaeda in Yemen. Despite being ready with a roughly 40-man special operations team and days to plan the operation, U.S. photojournalist Luke Somers and South African teacher Pierre Korki both died shortly after the midnight raid. The key problem, officials told the Wall Street Journal, came when some kind of sound alerted militants who were holding the hostages that the special operations team was nearby. The militants were part of al Qaeda in the Arabian Peninsula,...