PARIS • It took more than 12 hours to fully extinguish the flames that ripped through the Notre-Dame Cathedral. It will take many years for a shocked nation to restore one of its defining icons.
The cause of the fire, which began after the building was closed to the public on Monday evening, was still unknown.
However, Paris prosecutor Remy Heitz said that nothing indicates it was started deliberately, adding that a non-criminal investigation has been opened, a common step in such a major incident.
President Emmanuel Macron vowed: "We will rebuild Notre-Dame because that is what the French people want."
Meanwhile, hundreds of millions of euros have already been pledged to rebuild the cathedral.
Yesterday, after firefighters had put out the last smouldering remains of the fire, the devastation it caused could be seen in shards of stained glass from priceless mediaeval windows, and a gaping hole above the choir area where the spire crashed down.
The fire raged for hours, taking with it about two-thirds of the roof and the spire, and at one point even the stone structure of the monument was at risk.
French media reported that the fire may be linked to renovation work on the roof and the spire, which dated back to a 19th-century restoration.
The cathedral was covered in scaffolding on Monday for res-toration work, which fire experts said can expose ageing houses of worship to open flames or sparks from equipment.
The entire structure was a half-hour away from collapsing before firefighters prevented the blaze from engulfing the bell towers, according to Deputy Interior Minister Laurent Nunez.
Thousands of Parisians and tourists watched in horror from nearby streets as flames licked the building and officials tried to save as much as they could of the cathedral's countless treasures, built up over centuries.
Culture Minister Franck Riester said major treasures such as the "crown of thorns" and Louis IX's tunic were moved to City Hall, while other relics were taken to the Louvre museum.
Mr Michel Picaud, president of the Friends of Notre-Dame de Paris, said that the initial budget to restore the cathedral before the fire was about €150 million (S$230 million), and may need to be increased to about €450 million now.
Billionaires and local governments pledged nearly €700 million yesterday to help restore Notre-Dame, with foundations and crowdsourcing sites also launching fund-raising drives.
Reconstruction of Notre-Dame will take decades to complete, said the chief architect at Germany's Cologne Cathedral, Mr Peter Fuessenich.
The next few days are crucial because the stone vaults below the burned roof trusses have been soaked with the water used to extinguish the fire, he noted.
"This has led to a gain in weight many times over in the vaulted ceilings. One will have to wait over the next few days to see if the vaults will withstand this weight," said Mr Fuessenich.
The fire brigade said that after a "bitter battle" to douse the flames, firefighters were able to maintain the edifice's structure and rescue the cathedral's most important artworks, adding that two police officers and one firefighter had sustained slight injuries.
Mr Nunez said that specialists had found "some weaknesses" in the cathedral following the fire, especially in the dome. However, he added, the structure is holding quite well overall.
Calls from world leaders, including United States President Donald Trump, poured in yesterday morning to express their condolences. President Macron was slated to discuss the fire with Pope Francis later in the day, his office said.
French Prime Minister Edouard Philippe called a ministerial round for consultations on Notre-Dame's reconstruction.
Yesterday, Parisians and visitors were struggling to absorb the enormity of the disaster.
"I am devastated, even if I have not been a Catholic for a long time," 88-year-old Claire said at the scene yesterday morning. "I was baptised here."
Mr Philippe Marsset, the vicar-general of Notre-Dame, was among the first to enter the storied Gothic cathedral whose sculpted arches had been blackened by smoke and pews destroyed.
"It felt like I was looking at a bombing," Mr Marsset said of the church where he was ordained a priest 31 years ago.
"My bed was right there," Mr Marsset added, pointing towards the cathedral.
But in a luminous sign of hope, a golden cross was still intact at the back of the cathedral, shining defiantly in the gloom.
AGENCE FRANCE-PRESSE, BLOOMBERG, DPA, NYTIMES