Four hundred firefighters are currently battling a blaze at the Notre Dame Cathedral, which caught fire earlier today, at around 7 p.m. CEST, due to unknown causes, in Paris, France.

The dome collapsed earlier today, with the rest of the building currently alight. As of late Monday night, both of the cathedral’s towers were safe, according to Laurent Nunez, secretary to the interior minister.

Parisians have gathered around the structure, one of Paris’s most iconic attractions, for hours now, humming hymns since the burning spire collapsed into itself and fell onto the burning roof.

“Notre-Dame is aflame. Great emotion for the whole nation. Our thoughts go out to all Catholics and to the French people. Like all of my fellow citizens, I am sad to see this part of us burn tonight,” said French President Emmanuel Macron.

News spread via social media and phone calls to family, and across the world, people are anxiously watching the progress of the Parisian firefighters as they battle the flames.

“It’s a symbol of history, it’s a symbol of religion, and it’s a symbol of France itself. Everyone in France is just so heartbroken. I’ve already gotten calls from my grandparents about it,” Raphael Sanche (12) said. “There’s nothing we can really do—it’s just horrified silence at this point.”

Throughout the day, smoke and flames billowed in the wind as rescue workers rapidly evacuated works of art from inside the building. So far, one firefighter was injured in the process of battling the blaze.

“I think it’s the saddest thing I’ve heard in a very long time,” said Harker parent Prabha Krishna, who lived in France until she was 21 years old. “The impact on most people is huge. I was just saddened by the fact because it’s such a fixed icon of the site and such a fixed representation of the city, of something wonderful. You really feel humbled when you stand next to the Notre Dame—its presence, its beauty, its majesty.”

The cathedral, whose construction dates back to the fourteenth century, is a symbol of French culture and has become an icon of France itself. To tourists to residents alike, Notre Dame has been celebrated as a monument rich with cultural and historical significance.

“This is a place that is very important, not just for French people but humanity in general,” upper school French teacher Galina Tchourilova said.

Macron has announced that the French government will rebuild the structure after the flames are quelled.

“I think what makes me the saddest is that they can rebuild the building,” said upper school English teacher Ohad Paran, whose grandmother has an apartment in Paris that he visits often. “The thing is, is that it’s not just a building to visit. It was also a museum, so it had artwork and rare books and all of the things that were in it—like the furniture, the pews and stained glass windows and all those things—were hundreds of years old. So even though they’ll find a way to recreate it, it won’t be the same. It’ll be a copy at this point. Those things—you can’t put a dollar value on them because they are beyond value and they’re totally irreplaceable.”

The cause of the fire is currently unknown. Emergency services were notified of a fire in the attic of the cathedral and encountered difficulties when assessing the scene during the daily afternoon rush hour.

Additional reporting by Alysa Suleiman.