French President Emmanuel Macron has vowed to rebuild the medieval cathedral of Notre-Dame after a major fire partially destroyed the Paris landmark.
Firefighters managed to save the 850-year-old Gothic building's main stone structure, including its two towers, but the spire and roof collapsed.
The fire was declared under control almost nine hours after it started.
The cause is not yet clear but officials say it could be linked to extensive renovation works under way.
The Paris prosecutor's office said it was currently being investigated as an accident. A firefighter was lightly injured while tackling the blaze, Commander Jean-Claude Gallet told BFM TV.
The fire began at around 18:30 (16:30 GMT) and quickly reached the roof of the cathedral, destroying its stained-glass windows and the wooden interior before toppling the spire.
Fears grew that the cathedral's famous towers would also be destroyed by the blaze.
But while a number of fires did begin in the towers, French Interior Minister Laurent Nuñez said they were successfully stopped before they could spread.
By the early hours of Tuesday, the fire was declared under control, although it is expected to take several days to be completely extinguished.
What is the damage?
Search teams had already begun assessing the extent of the damage when dawn broke over the French capital. The cathedral's blackened stone and charred scaffolding were revealed to onlookers for the first time.
According to fire brigade spokesman Lt-Col Gabriel Plus "the whole of the roof has been devastated... a part of the vault has collapsed, the spire is no more".
However, it could have been much worse. Mr Nuñez said that, had fire crews not entered the building, "without doubt it would have collapsed", French newspaper Le Monde reported.
Franck Riester, France's culture minister, warned that while the principal structure had been saved, the building was still unstable.
What happens next?
Already, individuals and groups are mobilising to help rebuild Notre-Dame. Hundreds of millions of euros have already been pledged.
Billionaire François-Henri Pinault, chairman and CEO of the Kering group that owns the Gucci and Yves Saint Laurent fashion brands, pledged €100m (£86m; $113m) towards rebuilding Notre-Dame, AFP news agency reports.
Another €200m was pledged by Bernard Arnault's family and their company LVMH - a business empire which includes Louis Vuitton and Sephora - on Tuesday morning, according to Reuters news agency.
The French charity Fondation du Patrimoine is launching an international appeal for funds for the cathedral, a Unesco World Heritage site.
Visiting the scene on Monday night, Mr Macron - who said the "worst had been avoided" with the preservation of the cathedral's main structure - pledged to launch an international fundraising scheme for the reconstruction.