Moon and Japan's top government spokesman on Tuesday expressed their sympathy to French President Emmanuel Macron and the French government. Moon said the French people's "spirit of liberty, equality and fraternity will never be dashed by flames."
And Japan's chief cabinet secretary Yoshihide Suga says, "Its damage is a loss to the world and our hearts ache." The fire Monday felled the spire and burned through much of the roof, but fire officials said the flames had been stopped before reaching the north belfry. Most of its artwork and religious relics were said to have been saved as well.
People in the art world watched with shock and wept as a fierce fire ripped through Notre Dame Cathedral in Paris.
One medieval art expert called the Gothic church built over centuries "one of the great monuments to the best of civilization."
Barbara Drake Boehm, senior curator at the Metropolitan Museum of Art's medieval Cloisters branch in New York, said the flames were a reminder: "Civilization is just so fragile."
Her voice shook as she tried to put what Notre Dame means into words.
Others expressed fear for works of art inside the cathedral, including the famous stained-glass rose windows.
The fire chief in Paris said late Monday that hundreds of firefighters tackling the blaze saved Notre Dame by stopping the blaze before it could spread to the north belfry.
A hole left by Notre Dame's fallen spire is still burning and sparks are spilling down from the cathedral's vaulted ceilings more than five hours a fire broke out near the top of the Gothic landmark in Paris.
An Associated Press reporter entered the cathedral late Monday while French President Emmanuel Macron was visiting Notre Dame, getting a glimpse of the immense damage the blaze caused.
No lights were on, but the simmering red hole from the fallen spire provided illumination. Streams of sparks rained from the gap onto the floor where the church choir usually stands during services.
Paris Mayor Anne Hidalgo said earlier that most artworks and religious relics were removed from Notre Dame as firefighters worked to control the blaze.
France's culture minister posted photos on social media of people loading art onto trucks.
French President Emmanuel Macron has promised to rebuild Notre Dame Cathedral and says he is seeking international help to restore the Paris landmark.
Macron said after the French capital's fire chief announced the emergency response had changed into a monitoring and mop-up operation, "The worst has been avoided although the battle is not yet totally won."
Macron said a national fundraising campaign to restore Notre Dame would be launched Tuesday and he called on the world's "greatest talents" to help.
The French leader credited the "courage" and "great professionalism" of firefighters with sparing Notre Dame's facade and two landmark towers from being destroyed.
The Paris prosecutors' office says investigators are treating the blaze that destroyed part of Notre Dame as an accident for now.
The prosecutors' office said late Monday they have ruled out arson in Monday's fire, including possible terror-related motives for starting the blaze.
Prosecutors say Paris police will conduct an investigation into "involuntary destruction caused by fire."
A French official and the Paris fire chief say they think Notre Dame Cathedral's landmark rectangular towers have been saved from the fire that caused horrific damage.
Junior Interior Minister Laurent Nunez said late Monday that authorities remain "prudent" but are "much more optimistic" than earlier in the night.
Paris fire commander Jean-Claude Gallet said a major accomplishment of hundreds of firefighters was stopping the flames from spreading to the north tower belfry.
Gallet says two-thirds of Notre Dame's roofing "has been ravaged." He says one firefighter was injured.
He says fire crews will keep working overnight to cool down the structure.
The mayor of Paris says people who live near Notre Dame Cathedral have been evacuated in preparation for the burning structure's possible collapse.
But Mayor Anne Hidalgo said late Monday that firefighters were optimistic they could keep the towers that bookend the famous cathedral from going up in flames.
The fire chief in Paris went even further, saying his crews managed to stop the flames from reaching the belfry and prevented a catastrophic collapse.
Gallet says one firefighter was injured.
Hildago says the significant collection art work and holy objects kept inside the church has been recovered.
Parisians have gathered to say prayers and sing hymns In front of the nearby Saint Julien Les Pauvres church as the massive blaze at Notre Dame Cathedral burns only a few hundred meters away.
Flames and smoke rose in the sky behind the singers. A couple hundred people kneeling in prayer at the center of a larger group, who are standing around the edge and joining in the hymns between the prayers.
Paris archbishop Michel Aupetit is inviting priests across France to ring the bells of their churches in a call for prayers for Notre Dame.
Aupetit is at the cathedral and will meet with French President Emmanuel Macron later Monday night.
An official from the French Interior Ministry says 400 firefighters are at the scene of the fire but might they not be able to save Notre Dame Cathedral in Paris.
Laurent Nunez, speaking to reporters at the scene, says the devastating fire is not limited yet to a certain area and might continue to expand. He says cause of fire at the cathedral is unknown.
A group of Americans from Maine had just finished visiting Notre Dame Cathedral and were in a nearby park when they heard it was on fire.
Freeport resident Lucy Soule, 22, said it was "weird" having been in the church right before this happened. "Now you can smell it burning."
Soule and her father, Win Soule, 58, and Libby Heselton, 53, are on a weeklong trip to Paris where they planned to "see all the sights" and had just finished their visit to Notre Dame. They had been in the cathedral at 5:30 p.m., about an hour before the fire.
Win told The Associated Press "Now I feel sorry for the people tomorrow. They won't be able to see it."
He says "it's incredible. I'm not religious, but this is clearly very important to a lot of people."
The fire chief in Paris says it's unclear if city firefighters will be able to keep a fire at Notre Dame from spreading and causing more destruction.
Fire Chief Jean-Claude Gallet said outside the iconic cathedral as his crews battled the blaze from both the exterior and interior: "We are not sure we are capable of stopping the spreading" to Notre Dame's second tower and belfry.
Gallet said: "If it collapses, you can imagine how important the damage will be."
Flames already have reached one of Notre Dame's towers and brought down the church spire that extended 96-meters-high (315-feet.
The Vatican has issued a statement about the "terrible fire" that has "devastated" Notre Dame Cathedral in Paris.
The Vatican said: "The Holy See has seen with shock and sadness the news of the terrible fire that has devastated the Cathedral of Notre Dame, symbol of Christianity in France and in the world."
The statement says the Vatican is praying for firefighters "and those who are doing everything possible to confront this dramatic situation" on Monday.
It also expressed "our closeness to French Catholics and the population of Paris, and we assure our prayers for firefighters
French President Emmanuel Macron is treating the fire gutting Notre Dame Cathedral as a national emergency.
Macron reached the landmark cathedral on Monday evening and went straight into meetings at the nearby Paris police headquarters.
France's civil security agency says "all means" except for water-dropping aircraft were deployed to tackle the blaze.
The defense agency said those were unsuitable for fires like the one at Notre Dame because dumping water on the building could cause the whole structure to collapse.
The mammoth fire that destroyed the spire of Notre Dame Cathedral has spread to one of the church's landmark rectangular towers.
An Associated Press reporter at the scene of Monday's fire in Paris watched the flames blazing behind an oblong stained-glass window in the tower.
Paris police say fighters are inside the cathedral working to put the flames out while others work from the exterior. Red smoke is pouring out of the cathedral.
A Notre Dame spokesman said earlier that the church's entire wooden interior was in flames.
French President Emmanuel Macron has arrived at Notre Dame.
French writer and historian Camille Pascal says a massive fire at Notre Dame Cathedral has caused "the destruction of invaluable heritage" and "we can be only horrified by what we see."
Pascal told French broadcaster BFMTV: "It's been 800 years that the Cathedral watches over Paris" and its bells pealed for both "happy and unfortunate events."
He recalled that Notre Dame's bells sounded a death knell after the November 2015 terror attacks in Paris.
Authorities are investigating if renovation work on the cathedral's fire was a factor in starting or spreading the fire.
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.
French President Emmanuel Macron says the fire consuming Notre Dame Cathedral is taking part of everyone in France with it.
Macron tweeted after the blaze broke out in the cathedral's spire on Monday he was sad to see "a part of us being on fire."
He extended "thoughts for all the Catholics and all the French."
His administration says Macron is heading to Notre Dame.
The deputy mayor of Paris says Notre Dame Cathedral has suffered "colossal damages" from a fire that started in the spire and caused it to collapse.
Speaking to BFMTV, Deputy Mayor Emmanuel Gregoire said first responders now trying to salvage the art and other priceless pieces stored in the cathedral.
A cathedral spokesman has said the entire wooden interior of the Notre Dame is burning and likely to be destroyed.
U.S. President Donald Trump has tweeted about the fire engulfing Paris' iconic Notre Dame Cathedral.
Trump wrote on Twitter after the fire broke out Monday: "So horrible to watch the massive fire at Notre Dame Cathedral in Paris" and made suggestions for how first responders should tackle it.
He said: "Perhaps flying water tankers could be used to put it out," adding: "Must act quickly!"
Firefighters were trying to contain the fire when the cathedral's spire collapsed. Authorities say the wooden interior now is burning.
The soaring spire of Notre Dame Cathedral in Paris has collapsed in flames, and a church spokesman says the entire wooden interior of the 12th century landmark is burning and likely to be destroyed.
A massive fire engulfed the roof of the cathedral in the heart of the French capital on Monday afternoon as Parisians watched in horror.
Notre Dame spokesman Andre Finot told French media: "Everything is burning, nothing will remain from the frame."
The cathedral is home to incalculable works of art and is one of the world's most famous tourist attractions.
The cause of the blaze isn't yet known, but scaffolding could be seen on the roof of the burning structure. The spire was undergoing renovation.
Police in Paris say the cause of the massive fire enveloping the spire of Notre Dame Cathedral isn't yet known.
The French capital's police department said no deaths have been reported from Monday's fire. The police department didn't say anything about injuries.
The peak of the 12th century cathedral is undergoing a 6 million-euro ($6.8 million) renovation project.
French media quoted the Paris fire brigade saying the fire is "potentially linked" to the renovation work.
Located on the Ile de la Cite in the center of Paris, the Gothic cathedral is among the most famous from the Middle Ages and was built on the ruins of two earlier churches.
French President Emmanuel Macron has postponed a televised speech to the nation because of a massive fire enveloping the top of Notre Dame Cathedral in Paris.
Flames are shooting out of the roof behind the nave of the 12th cathedral, one of the world's most visited landmarks.
The sight stopped pedestrians in their tracks along the Seine River, which passes under the cathedral.
Authorities said the fire could be linked to renovation work. It's unclear if anyone has been hurt in the fire.
Macron's pre-recorded speech was set to be aired later Monday on French TV. Macron was expected to lay out his plan to address the citizen complaints that gave rise to the yellow vest protests that have rocked France since November.
Paris Mayor Anne Hidalgo says firefighters are trying to contain a "terrible fire" at the city's Notre Cathedral.
An AP reporter at the scene of Monday's fire says the roof at the back of the cathedral, behind the nave, is in flames and yellow-brown smoke and ash fill the sky.
Hidalgo urged residents of the French capital to stay away from the security perimeter around the Gothic-style church. The mayor says city officials are in touch with Roman Catholic diocese in Paris.
Firefighters are battling a massive blaze at the French capital's iconic Notre Dame Cathedral.
Flames and black smoke were seen shooting from the base of the medieval church's spire on Monday.
The peak of the church is undergoing a 6 million-euro ($6.8 million) renovation project.
French media quoted the Paris fire brigade saying the fire is "potentially linked" to the renovation work.