Some details of the chronology of Monday's fire are beginning to emerge.
At 6:20 p.m. local time (12:20 p.m. ET), security guards at the Notre Dame first heard the fire alarm and evacuated the cathedral, even though they didn't see any sign of a fire, a spokesman for the Paris fire brigade told CNN.
The fire alarm rang again at 6:43 p.m. local time (12:43 p.m. ET). That's when the cathedral’s security officers noticed the fire, Paris Prosecutor Rémy Heitz confirmed during a press conference on Tuesday.
9:42 a.m. ET, April 16, 2019
Companies pour more money into rebuilding fund
As Paris looks to restore its iconic cathedral to its former glory, it appears funding won't be an issue.
French cosmetics company L'Oréal, along with The Bettencourt Meyers family and the Bettencourt Schueller Foundation, have said they will donate 200 million euros ($226 million) to the restoration efforts.
That puts the amount of donations so far from French tycoons and businesses, confirmed by CNN, at 601 million euros ($679 million).
That total doesn't include money from the city of Paris and the French government.
9:01 a.m. ET, April 16, 2019
Workers remove precious artworks from cathedral
Paris mayor Anne Hidalgo has tweeted a video of artworks being carefully removed from Notre Dame and taken away for preservation and protection.
Items rescued from the blaze include the Crown of Thorns, which some believe was placed on the head of Jesus during the crucifixion, and the linen Tunic of St Louis.
The works are being sent to Paris City Hall and to the Louvre museum for safekeeping.
8:59 a.m. ET, April 16, 2019
Paris mourns its 'Lady' after Notre Dame inferno
From CNN's Eliza Mackintosh
At dawn on Tuesday, as the first blush of sunrise illuminated Notre-Dame de Paris, residents gathered on the left bank of the river Seine to see the damage wrought by a devastating fire that had engulfed the historic cathedral overnight.
"For me, it's much more than stones, it's a part of myself that is burning," said Sarah Virot, 32, who works for a Christian association in the capital.
Notre Dame sits at the French capital's geographical and psychological heart, on a small island called the Île de la Cité, embraced on both sides by the Seine.
It's not just the center of the city, but of the country; from it, all other distances to the capital are measured. And so, for Parisians, the cathedral is not just a religious structure, but a shared legacy.
"I came because I wanted to see something that was hard to imagine," Sarah Parent du Châtelet, 33, told CNN. "I was born in Paris and I know this lady just like an immortal person. It's impossible to imagine Paris without her."
If the Eiffel Tower came to signify the city's sparkling future, Notre Dame has, for generations, embodied its past. "She is the heart of Paris, eternal and spiritual," Parent du Châtelet added.
British cathedral hit by fire sends support to Notre Dame
News of the devastating fire at Notre Dame will have struck a familiar note to many in York, in northern England.
York Minster, the city's gothic cathedral, was hit by a similar disaster in 1984 when a fire partially destroyed the building.
Both churches can be traced back to a similar time period; Notre Dame was completed in the mid-13th century, while York Minster's West Window and other parts of the site date back to the 14th century.
On Tuesday, York Minster tweeted that the cathedral community had been "shocked and saddened" to see the damage at Notre Dame.
The Archbishop of York, John Sentamu -- the second most senior bishop in the Church of England -- said he had held prayers for Notre Dame on Tuesday morning.
York Minster was painstakingly restored over four years at a cost of just £2.25 million (about £7 million, or $9 million, in today's money).
In terms of structural damage, Notre Dame may be in better condition, since its vault was primarily made of stone, not wood.
8:21 a.m. ET, April 16, 2019
How to rebuild a gothic cathedral
From CNN's Oscar Holland
Those looking for hope amid the devastation of Notre Dame will be heartened by French President Emmanuel Macron's assurance that the French will "rebuild together," and immediate fundraising efforts leading to pledges of 50 million euros ($56 million) and 200 million euros ($226 million) from Paris' City Hall and the luxury goods and fashion house LVMH, respectively.
Assuming the requisite funding is found, how will the process be carried out?
Before distinguishing between the salvageable and the unrecoverable, immediate steps will need to be taken to prevent further damage, architectural historian and broadcaster Jonathan Foyle explains.
"It's already a wet building because of the water that's been pumped on it, so they're going to need to provide some kind of cover from the elements," he told CNN.
"The roof's job was to discharge thousands of tons of water, so where's that going to go? Every time it rains it's going to cause damage at this point, so it's a war of attrition now."
French authorities will ultimately need to take a series of design decisions over how best to rebuild. To do so, they will need to better understand how the medieval cathedral was constructed in the first place.
But the goal of restoration is not always to replicate the past, and modern tastes and technologies may influence how damaged structures are reimagined.
Paris police architects and experts have identified “some vulnerabilities” in the structure of Notre Dame after inspecting the cathedral on Tuesday, Junior Interior Minister Laurent Nunez says.
“Overall the structure is good but some vulnerabilities have been identified especially at the level of the vault, the ceiling and to part of the northern transept,” Nunez said, adding that five residential buildings nearby have been evacuated.
The 850-year-old cathedral was being worked on at the time of the fire, with scaffolding around part of its structure.
7:57 a.m. ET, April 16, 2019
Pope Francis: Sorrow will turn to hope
Pope Francis has tweeted his condolences to the people of France, following the fire at the 850-year-old Catholic cathedral.
11:10 a.m. ET, April 16, 2019
Firefighters saved many precious artworks from the Notre Dame blaze
Many of the most valuable works of art inside Notre Dame Cathedral were saved by firefighters and have been relocated to safety, French Culture Minister Franck Riester told reporters on Tuesday.
Items rescued include the Crown of Thorns, which some believe was placed on the head of Jesus and which the cathedral calls its "most precious and most venerated relic." The linen Tunic of St Louis was also saved, and both items have been moved to Paris City Hall, Riester said.
Other works are being taken to Paris' renowned art museum, the Louvre, and relocation will continue throughout Tuesday and Wednesday.
"As for the large artwork, the “May de Notre-Dame”, this can be moved from Notre-Dame from Friday morning," he said. "It seems from a first examination that while the fire has not caused any damage, there is some smoke damage."
"We’ll move these items safely to the Louvre storage facilities, where they will be dehumidified, protected, conserved and restored," he added.
Riester also said the famous rose windows at the north and south of the cathedral "do not appear for now to have sustained catastrophic damage."