The Islamic State group has taken control of the ancient Syrian city of Palmyra, a UNESCO World Heritage Site after days of fierce fighting forced government troops to withdraw. ISIS has reportedly begun the massacre of a rebellious tribe and faces no opposition to the destruction of the city’s ruins. The fall of Palmyra, coming shortly after that of Ramadi in Iraq, has put new pressure on Damascus and Bagdad, but also calls into question the U.S. strategy of relying on airstrikes to fight against the Islamic State. Syria’s Antiquities Director said the world must mobilize to save ancient Palmyra. Nashwan Abdullah reports from Damascus.