The mood in Paris today is somber after a fire ripped through the Notre Dame Cathedral. The iconic structure took more than 200 years to build and just a few hours to burn. It's rich with history, serving as a setting to crown kings and celebrate the liberation of Paris from the Nazis. As French authorities assess the damage and craft plans to rebuild the monument, Bloomberg's Tom Keene, Bob Moon and Annmarie Hordern reflect on the moment.