Air France is to offer free flights to people involved in the reconstruction of the Notre Dame Cathedral in Paris. The 850-year-old cathedral was extensively damaged in a fire Monday night that ripped through its spire and roof for several hours, shocking people around the world. More than 600m euros have already been pledged to restore the cathedral, one of the world’s iconic cultural attractions. READ:  Air France innovations help take the stress out of travel. Although the famous bell towers and rose windows remain intact, there is damage to the building's medieval wooden structures as well as worries about the effect of the fire on its stonework and even its much-photographed gargoyles. Some experts are asking whether the work of the original artisans can be recreated but the feeling is strong that it should be rebuilt. French President Emmanuel Macron this week pledged to rebuild the cathedral within five years, saying  France will mobilize for the effort. “We are a people of builders,’’ he said. “We have so much to rebuild and we will rebuild. We will make it even more beautiful than before and I want it done within the next five years.” However, experts say the project could take a decade and possibly longer. The French national carrier, part of the wider Air France-KLM Group, said staff had been deeply affected and saddened by the fire. It said Air France-KLM chief executive Benjamin Smith had joined with the aviation group’s president and Air France chief executive Anne Rigail to allow the carrier to “ensure the free transport of all the official actors who will take part in the reconstruction of Notre-Dame Cathedral in Paris”. "In addition, the Air France-KLM Group will set up a voluntary collection system for its customers in the coming days to help finance the reconstruction work," it said. Other companies to pledge support for the reconstruction include tech giant Apple as well as the owners of investment firm Artemis, luxury brand LVMH and L’Oreal.