The battle for Mosul, Iraq.  Correspondent Tony Cheng is just back from the front lines of the months-long allied campaign to expel the Islamic State, ISIS, from its most important city. American air power has been crucial in this fight, but has also been the cause of many civilian casualties, which are starting to run into the thousands.  And Tony also explains why reporters covering today’s wars always try to keep their feet and their vehicles on pavement.