Pope Francis is offering his prayers that Notre Dame, the "architectural gem of a collective memory," will once again be a shrine to the Catholic faith, a symbol of the French nation and a spiritual and architectural gift to humanity.

In a heartfelt note of condolences sent to Paris Archbishop Michel Aupetit, Francis said Tuesday that the fire was particularly devastating given that it came during Holy Week, the somber days leading up to Easter during which Christians commemorate the death and resurrection of Jesus Christ.

Francis wrote: "This catastrophe has gravely harmed a historic building. But I am aware that it has also affected a national symbol dear to the heart of Parisians and all French people in the diversity of their convictions. Because Notre Dame is the architectural gem of a collective memory, a place of gathering for great events, a witness of the faith and prayer of Catholics in the heart of the city."

Francis praised the courage of the firefighters and invoked his blessings on the nation.