On Monday afternoon, the historic Notre-Dame cathedral was engulfed in flames — an incident that has spurred mourning both online and in the Paris streets, where people have coalesced to grieve the devastation of the iconic 12th-century landmark. While the story is developing, here’s what we know so far.

At approximately 6:50 p.m. local time, firefighters were dispatched to the Notre-Dame cathedral, out of which flames and black smoke were billowing. It wasn’t until 11:30 p.m. local time that the fire was reportedly contained.

As of yet, no official cause has been named. However, the AP reports that the Paris Fire Brigade believes the blaze is “potentially linked” to the 20-year, €6 million, long overdue renovation project the cathedral was undergoing. (Paris prosecutors believe the fire was started accidentally.)

An immense amount. CNBC reports that both the spire and the roof collapsed and that the flames spread to one of the cathedral’s towers. According to an unconfirmed Twitter report, the north, south, and west rose windows were destroyed. (Again, that information has not been confirmed.)

But, as France 24 reports, firefighters were able to save the cathedral from “complete destruction.” Both towers are reportedly still standing, and per another French journalist, most pieces of art and artifacts — notably, the crown of thorns — have been saved.

Per Paris police, there have been no confirmed deaths and no reported injuries.

In Paris, locals have gathered outside the cathedral to weep and mourn the devastation through hymns.

French president Emmanuel Macron treated the fire as a national emergency, writing on Twitter as the fire raged on, “I am sad to see this part of us burn tonight.” But after firefighters put out the flames, he took a more optimistic tone, vowing to reporters in French, “Notre-Dame will be rebuilt.”

Former president Barack Obama also extended his condolences to France on Twitter, writing that it’s “in our nature to rebuild for tomorrow, as strong as we can.” (Trump tweeted too.)

Even New York City mayor Bill de Blasio weighed in, saying in a statement that “New York City is mourning with Paris.”