French President Emmanuel Macron has vowed to restore Notre-Dame Cathedral within five years in a televised address to his nation - shaken by the fire that swept through the historic structure.
A colossal fire caused the spire of the edifice in Paris to crash to the ground and wiped out centuries of heritage.
In his televised address, Mr Macron again promised the cathedral would be restored.
"We will rebuild the cathedral even more beautifully within five years," Mr Macron said in an address to the nation a day after the blaze.
Mr Macron expressed relief that "the worst had been avoided" in a fire that risked bringing the entire spire down and left France in shock over the damage to a building described as the soul of the nation.
“It is up to us to change this disaster into an opportunity to come together, having deeply reflected on what we have been and what we have to be and become better than we are," President Macron said.
"It is up to us to find the thread of our national project.”
French President Emmanuel Macron has vowed to rebuild the cathedral. Source: EPA
But he also warned: "Let us not fall into the trap of haste."
Mr Macron said that the dramatic fire had brought out the best in a country that has been riven with divisions.
"What we saw last night in Paris was our capacity to mobilise and to unite," the 41-year-old leader said in the solemn address from his office in the presidential palace.
France had over the course of its history seen many towns, ports and churches go up in flames, he said.
"Each time we rebuilt them," he said, adding that the cathedral inferno had shown that "our history never stops and that we will always have trials to overcome."
'Our history never stops'
Mr Macron's defiant comments indicated he wants the reconstruction of the cathedral to be completed by the time Paris hosts the Olympic Games in 2024.
"We will rebuild the cathedral even more beautifully and I want it to be finished within five years," Mr Macron said from the Elysee Palace. "And we can do it."
Mr Macron said that the dramatic fire had brought out the best in a country riven with divisions and since November shaken by sometimes violent protests against his rule.
"What we saw last night in Paris was our capacity to mobilise and to unite," Mr Macron said, hailing France as a nation of "builders".
"Our history never stops and that we will always have trials to overcome," he said.
A hole is seen in the dome inside the damaged Notre Dame cathedral in Paris. Source: EPA
'Saved in half an hour'
Images from inside the cathedral Tuesday showed its immense walls standing proud, with statues still in place and a gleaming golden cross above the altar.
However the floor was covered in charred rubble from the fallen roof and water while parts of the vaulting at the top of the cathedral had collapsed.
Junior interior minister Laurent Nunez told reporters at the scene that work to secure the structure would continue into Thursday, allowing firefighters access to remove remaining artifacts and artworks.
He said the building had been saved within a critical time window of 15-30 minutes by a team of 400 firefighters who worked flat out throughout the night.
Flames and smoke rise as the spire of Notre Dame cathedral collapses. Source: Getty Images
Though "some weaknesses" in the 850-year-old structure had been identified, overall it is "holding up OK", he added.
President Donald Trump relayed Americans' "condolences" to Mr Macron over the fire, the White House said.
French fire chiefs had earlier dismissed as "risible" comments by Trump that the fire should be tackled with water bombers, saying this risked destroying the entire edifice of the cathedral.
The Paris fire service said that the last remnants of the blaze were extinguished Tuesday, 15 hours after the fire broke out.
Renovation work on the steeple, where workers were replacing its lead covering, is widely suspected to have caused the inferno after the blaze broke out in an area under scaffolding.
Investigators interviewed witnesses overnight and began speaking with employees of five different construction companies that were working on the monument, said public prosecutor Remy Heitz.
"Nothing indicates this was a deliberate act," Heitz told reporters, adding that 50 investigators had been assigned to what he expected to be a "long and complex" case.
Debris is seen inside the damaged Notre Dame cathedral in Paris. Source: EPA
'For future generations'
A public appeal for funds drew immediate support from French billionaires and other private donors as well as from countries including Germany, Italy and Russia which offered expertise.
French billionaire Bernard Arnault and his LVMH luxury conglomerate, rival high-end designer goods group Kering, Total oil company and cosmetics giant L'Oreal each pledged 100 million euros or more.
Support came from outside France as well, with Apple chief Tim Cook announcing the tech giant would give an unspecified amount to help restore a "precious heritage for future generations."
But experts had warned a full restoration will take many years. "I'd say decades," said Eric Fischer, head of the foundation in charge of restoring the 1,000-year-old Strasbourg cathedral.
ImageTreasures evacuated
Thousands of Parisians and tourists watched in horror Monday as flames engulfed the building and rescuers tried to save as much as they could of the cathedral's treasures.
Many more came Tuesday to the banks of the river Seine to gaze at where the roof and steeple once stood.
A firefighter suffered injuries during the blaze, which at one point threatened to bring down one of the two monumental towers on the western facade of the cathedral that is visited by 13 million tourists each year.
The Holy Crown of Thorns, believed to have been worn by Jesus at his crucifixion, was saved by firefighters, as was a sacred tunic worn by 13th-century French king Louis IX.
Rescuers formed a human chain at the site of the disaster to evacuate as many artifacts as possible, which were then stocked temporarily at the Paris town hall.
More than 400 firemen were needed to tame the inferno that consumed the roof and collapsed the spire of the gothic masterpiece. They worked through the night, finally quelling the blaze some 14 hours after it began.
“Yesterday we thought the whole cathedral would collapse. Yet this morning she is still standing, valiant, despite everything,” said Sister Marie Aimee, a nun who had hurried to a nearby church to pray as the flames spread.
French President Emmanuel Macron (C) looks inside the Notre-Dame Cathedral after the massive fire burnt the roof of the iconic building. Source: EPA
But the blaze destroyed the roof of the 850-year-old UNESCO world heritage landmark, whose spectacular Gothic spire collapsed before the eyes of horrified onlookers on a previously pristine early spring evening.
Gasps and cries of "Oh my god" erupted at 7:50 pm when the top portion of the church's spire came crashing down into an inferno that has spread to the entire roof.
More gasps came a few seconds later when the rest of the spire collapsed, caught on the cameras of thousands of mobile phones.
"Paris is disfigured. The city will never be like it was before," said Philippe, a communications worker in his mid-30s, who had biked over after being alerted of the fire by a friend.
"I'm a Parisian, my father was a Parisian, my grandfather as well - this was something we brought our sons to see," he said. "I won't be showing this to my son."
The steeple engulfed in flames collapses as the roof of the Notre-Dame de Paris Cathedral burns. Source: Getty Images
"It's a tragedy," he added. "If you pray, now is the time to pray."
Onlookers sang liturgical songs such as Hail Mary and Ave Maria, as the inferno raged at the cathedral. Others knelt and prayed.
The cathedral is home to incalculable works of art and is one of the world's most famous tourist attractions.
The main structure of the cathedral and the two bell towers have been saved after hours of fire-fighting, the city's top fire official said.
"We can consider that the main structure of Notre-Dame has been saved and preserved," Paris fire brigade chief Jean-Claude Gallet told reporters outside the cathedral.
He said that the main task now was to cool the temperature inside the cathedral, a procedure that would take several hours, and to save the artwork inside.
Notre-Dame’s top administrative cleric, Monsignor Patrick Chauvet, said a centuries-old crown of thorns made from reeds and gold, and the tunic worn by Saint Louis, a 13th century king of France, were saved,.
But he said firefighters had struggled to take down some of the large paintings in time.
The cause of the fire is still unknown, but could be linked to renovations taking place.
The Paris prosecutor's office said it has opened an inquiry into "accidental destruction by fire".
The interior of the cathedral as emergency services continue to work. The two towers and facade have been saved. Source: AP
Mr Macron confirmed the 'worst has been avoided', thanking rescue workers for saving Notre-Dame's two towers and facade.
"We will rebuild Notre-Dame," he said, after he visited the famed Paris cathedral.
However, the historic building's roof and iconic steeple have been gutted by fire.
Bystanders look on as flames and smoke are seen billowing from the roof at Notre-Dame Cathedral. Source: AP
Police were attempting to clear pedestrians away from the two islands in the river Seine, including the Ile de la Cite which houses the soaring Gothic church, one of Europe's best known landmarks.
President Macron expressed the "emotion of a whole nation" on seeing the famed cathedral ablaze and its spire collapsed.
But throngs of onlookers kept trying to approach, snarling traffic as they massed on the stone bridges leading to the islands.
Another woman passed by, tears streaming from behind her glasses, too overwhelmed to speak to reporters.
"It's finished, we'll never be able to see it again," said Jerome Fautrey, a 37-year-old who had come to watch.
"Now we need to know how this happened - with everything that's going on in the world, why Notre-Dame? Maybe it's a message from on high," he said.
'History up in smoke'
"It's incredible, our history is going up in smoke," said Benoit, 42, who arrived on the scene by bike.
Sam Ogden, 50, had arrived from London on Monday with her husband, their two teenaged sons, and her mother. They had come to Paris specifically to see Notre-Dame, part of a world tour over years to see historic sites.
"This is really sad - the saddest thing I've ever stood and watched in my life," Ogden said.
She said the fire looked tiny at the beginning, "then within an hour it all came down."
Her mother, Mary Huxtable, 73, said: "This (Notre-Dame) was on my bucket list to see. Now I'll never go inside."
A short distance away stood another British family, also from London.
"It's devastating," said Nathalie Cadwallader, 42, who had come to Paris two days earlier with her husband and two children for a weeklong visit.
"This is a really historic skyscape and it's horrible this happened, on top of everything else Paris has gone through recently," she said, referring to the deadly jihadist terror attacks that struck the city in 2015.
Her family had initially planned to visit Notre-Dame on Monday but opted instead for the Eiffel Tower, intending to go inside the cathedral on Tuesday.
WHAT WE KNOW ABOUT THE FIRE AT NOTRE-DAME CATHEDRAL:
- The fire broke out in the cathedral in the afternoon
- the spire of the 12th century cathedral is undergoing a 6 million-euro ($A9.5 million) renovation; some statutes removed last week
- The cause is unknown at this point; authorities are investigating if renovation work on the cathedral's fire was a factor in starting or spreading the fire
- Deputy mayor of Paris Emmanuel Gregoire says the fire started in the spire; he says first responders are trying to salvage the art and other priceless pieces stored in the cathedral.
- The wood and lead spire has collapsed as has the roof; flames are now in one of the rectangular towers
- A Notre-Dame spokesman said the church's entire wooden interior was in flames
- On Thursday, 16 religious statues were removed from the peak for the first time in over a century to be taken for cleaning and therefore escaped the blaze
- Firefighters have evacuated the area as well as the buildings on the island it stands on; the Gothic cathedral stands in the centre of Paris
- France's civil security agency says "all means" except for water-dropping aircraft were deployed to tackle the blaze. Dumping water on the building from the air could cause the whole structure to collapse.
- President Emmanuel Macron is treating the fire as a national emergency and is at the scene
- The French capital's police department says there have been no deaths.
