In 2018 the Catholic Church in France launched an urgent appeal for funds to save Notre-Dame cathedral.

Parts of the 850-year-old Gothic masterpiece were starting to crumble, because of pollution eating the stone.

At the time, Michel Picot, head of fundraising, took to the rooftop to show the extent of the challenge ahead.

After Monday's devastating fire, the task has grown immeasurably, but President Emmanuel Macron has vowed the cathedral will be rebuilt.