A fire has broken out at the famous Notre‑Dame cathedral in Paris and has spread rapidly across the building.
The cause is not yet clear, but officials say that it could be linked to renovation work.
A major operation to tackle the blaze is underway at the 850‑year‑old Gothic building, but the cathedral's spire and roof have collapsed.
Last year, the Catholic Church in France appealed for funds to save the building, which was crumbling.
Hundreds of people have gathered in the streets around the cathedral, observing the flames in silence.
French President Emmanuel Macron, who has arrived at the scene, said his thoughts were with "all Catholics and all French people."
Macron has cancelled his planned speech to the nation following the fire.
A spokesman for the cathedral said the whole structure was "burning".
Historian Camille Pascal told French media that the fire was destroying "invaluable heritage."
Pascal said that no other site represents France quite like Notre‑Dame. Its main rival as a national symbol, the Eiffel Tower, is little more than a century old. Notre‑Dame has stood tall above Paris since the 1200s.
It has given its name to one of the country's literary masterpieces. Victor Hugo's The Hunchback of Notre‑Dame is known to the French simply as Notre Dame de Paris.
The last time the cathedral suffered major damage was during the French Revolution. It survived two world wars largely unscathed.
The church receives almost 13 million visitors each year, more than the Eiffel Tower.