At least two-thirds of the roof of Notre Dame cathedral in Paris “is gone” after the devastating fire in Paris, but UN cultural experts have told UN News they are standing by to help the French Government rebuild the iconic structure. That’s according to UNESCO World Heritage Centre Director, Mechtild Rössler, who made several visits to the site on Tuesday, and spoke by phone to Daniel Johnson about what she had seen, and how the UN can play a role in restoring one of the world’s most famous and historic buildings.