As the flames billowed from the roof of Notre-Dame Cathedral Monday night, as the filigreed spire burned, then toppled into the inferno, it was easy to imagine the centuries-old structure would be lost — to Paris, to France, to the world.

But horrifying as the fire was, the stone exterior remained mostly intact, and — amazingly — so did much of the interior. And it’s now clear that Notre-Dame can and will be restored to its former glory.

“I tell you solemnly tonight: we will rebuild Notre-Dame,” said President Emmanuel Macron, standing before the still-flaming structure late last night. “Because that is what the French expect.”

Jack Lang, who twice served as France’s culture minister, was among the many who gathered on the banks of the Seine on Tuesday to survey the damage, reports NBC News. Lang said predictions that it would take “tens of years” to rebuild the cathedral were “unacceptable.”

“This is a monument that is dear to the heart of millions of people around the world,” he said. “It needs urgency.”

Already, hundreds of millions of euros have been pledged to the project, by companies like LVMH (Louis Vuitton Moët Hennessy), billionaire François-Henri Pinault, husband of the actress Salma Hayek, and other wealthy families.

The cathedral has stood for more than 800 years on the Île de la Cité, an island in the Seine River at the heart of the French capital. Inside it today, firefighters were still hunting for any remaining fire and investigators were seeking evidence of the fire’s cause.

The Paris prosecutor, Rémy Heitz, says it will be “a long and complex investigation,” but for now the disaster is thought to have been an accident, reports the New York Times.

“The nearly 50 investigators assigned to the case were focusing on interviewing workmen who had left the site but had been engaged in the restoration of the cathedral not long before the fire broke out,” the Times says.

In a tweet, the Vatican offered a look at the cathedral’s smoldering interior.

The flames erupted in the ancient wooden framework of the cathedral’s attic. Two fire alarms went off: the first was at 6:20 p.m., but no fire was found; 23 minutes later the second sounded, and the battle to save the Gothic masterpiece was on.

While hundreds of firefighters converged on Notre-Dame, churchmen struggled to save the many artifacts and works of art contained in the building.

“We made a human chain, with our friends from the church… to get, as quick as possible, to get all the relics,” Paris Deputy Mayor Jean-Francois Martins told “CBS This Morning” on Tuesday. Among the items rescued was the Crown of Thorns the faithful believe was worn by Jesus Christ on the cross.

CBS cited Britain’s Sky News as reporting “that the man at the hot end of the human chain, who quickly located the most iconic of relics … was Father Jean-Marc Fournier, chaplain of the Paris Fire Department.”

“According to a Notre Dame priest during the fire,” reports the Washington Post, “all of the art work had been removed,” much of it taken for restoration at the Louvre before the fire. “French Minister of Culture Franck Riester later clarified that religious relics had been saved and some of the art work inside had suffered smoke damage and was also being taken to the Louvre.”

Remarkably, says the Post, the famous South Rose stained-glass windows, created more than 750 years ago, appear to have survived undamaged.

Notre-Dame was built on the foundation of an earlier church, which had itself been constructed over ancient Roman defenses. Begun around 1160, it was largely completed nearly two centuries later, in 1345.

The wooden structure holding up the lead roof came from that time — and the ancient oak and chestnut beams were utterly dry. Once the flames erupted, they raced through the structure and up the spire, almost before firefighters could arrive.

“It wasn’t until late at night that a city official said the structure of the building — including its two famous bell towers — had been saved,” says NBC. “Crews had been battling the blaze for around nine hours.”

The building had just been closed to tourists and so was nearly empty. Two police officers and a firefighter were injured during the fire, but no one was killed.

Notre-Dame is one of the best-known and most-visited places in the world, drawing more than 12 million tourists a year.

It has been the site of many historic events, including coronations like that of  Napoleon Bonaparte in 1804 and the beatification of Joan of Arc in 1909; as a center of the French Revolution, when it was used by revolutionaries as a food warehouse; and, of course, as the backdrop for Victor Hugo’s beloved novel, “The Hunchback of Notre-Dame.”