PARIS, FRANCE—A fire at the seventeenth-century Hotel Lambert on the Île Saint-Louis has destroyed a large part of the building’s roof and a portion of the central staircase, in addition to severely damaging ceiling paintings by Charles Le Brun in the Gallery of Hercules. The historic mansion, once home to Voltaire, was purchased in 2007 by a Qatari prince and was being renovated. “It really is a catastrophe because we fought for the frescos of the Gallery of Hercules to be preserved in the renovation project and now everything has gone up in smoke or been drowned,” commented a neighbor.