In the offices of the French heritage foundation, near the banks of the Seine River just outside Paris, there's a buzz in the air.
Not only is the mood unusually febrile, but cellphones are literally buzzing and landlines are ringing off the hook.
The charity, whose official name is the Fondation du patrimoine, is acting as one of the government's main receivers of donations for the conservation — and eventual reconstruction — of Notre-Dame Cathedral.
More than 400 firefighters took part in the battle to save the 12th-century cathedral on Monday evening after the internationally revered church caught fire. Its spire collapsed and roof was destroyed, but its iconic towers, rose windows, famed organ and precious artworks were saved.
The emotional reaction of donors has been overwhelming, said the organization's CEO, Célia Vérot. People "are very sad. And they want to do something positive."
And so the donations have been pouring in at an unprecedented rate.
As of Wednesday night, the organization said it had raised €144.2 million ($172 million Cdn) for the project. That's only a fraction of the nearly €1 billion ($1.5 billion Cdn) pledged or donated overall, including hundreds of millions from corporations and wealthy French entrepreneurs.
The instant generosity, particularly from billionaires and large firms, hasn't been without criticism.
Personal stories of generosity
It is the smaller sums, however, that have come with the most compelling personal stories.
On Wednesday, foundation employee Ella Nègre was opening a first stack among the hundreds of envelopes containing cheques sent by mail.
She also sifted through donations made online. Nègre came upon one for the sum of 10 euros. In an email, a woman explained the amount represented her four-year-old granddaughter's "life savings."
Reading such stories "softens the blow of the loss," Nègre told CBC. "It's very sweet."
The heritage foundation's mandate is to protect France's culturally or historically significant infrastructure. Its website lists hundreds of churches and chapels at risk of falling into disrepair.
The CEO said the charity would normally receive contributions from 50,000 donors in a year. But in just the first 24 hours following Monday's fire, 100,000 individuals and companies had already contributed to the nascent campaign for Notre-Dame.
Pauline Vérove, an intern, finds herself fielding non-stop phone inquiries from would-be donors around the world.
A call from one woman in particular shook her. The caller had once visited Notre-Dame and vividly remembered seeing the medieval wooden roof frame, now lost to the flames.
"She was crying on the phone, telling me the story, and she really wanted to be able to give something, even if she never sees the reconstruction," Vérove said.
Watch out for scams
The heritage foundation has mounted an aggressive media campaign in France to warn potential donors of scams. Fraudsters have been trying to capitalize on the renown of the fundraising effort by posing as legitimate charity workers.
"Many scams have been flagged in France and abroad," the foundation said in a statement. "The Fondation du patrimoine does not send appeals by email, post or phone. All these efforts are fraudulent."
The organization says scammers have created fake Fondation du patrimoine pages on social media, or even sent out appeals for donations by email, posing as the foundation's president, Guillaume Poitrinal.
"Some crooks were swindling our compatriots," French Culture Minister Franck Riester acknowledged Thursday on BFM TV.
The government has listed four groups — including the Fondation du patrimoine — that are authorized to accept donations for the cathedral's future.
Real cost unknown
No one can say with any certainty how much restoration will cost, nor how long it will take.
When French President Emmanuel Macron pledged to have the work done in five years, he didn't include a price tag. But other famous European landmarks could provide clues.
England's Windsor Castle and the opera house in Barcelona went up in flames in 1992 and 1994, respectively. In both cases, it took five years — and tens of millions of dollars — of work before they could be reopened.
For Notre-Dame, a more apt comparison may be the restoration of Britain's Houses of Parliament, both for the size of the building and its degree of fame. After its aging infrastructure was found to pose a significant fire risk, the London icon is undergoing renovations that are expected to take more than a decade and cost at least £3.5 billion ($6.1 billion Cdn).
The French heritage foundation's CEO cited experts saying the total cost to fix Notre-Dame could reach €10 billion ($15 billion Cdn).
Long before any reconstruction starts, Vérot said, a massive cover will need to be placed above Notre-Dame to protect the cathedral and the work site. "That will be the first priority," she said.
"And I think it will be expensive."