COPENHAGEN, Denmark (AFP) — A huge fire on Tuesday tore through Copenhagen’s 17th-century former stock exchange, toppling the historic building’s landmark spire in front of horrified and emotional witnesses.

Amid flames and black smoke, the 54-metre (180-foot) spire crashed into the street below the the Borsen building, which had been undergoing renovation.

“This is our Notre-Dame! This is a national treasure,” local resident, 45-year-old Elisabeth Moltke, told AFP as she watched the blaze. Other witnesses watched in tears as more than 100 firefighters battled to save the building.

“A lot of old Danish paintings, originals are in there. I’ve been in there several times and it’s a magnificent building so it makes me feel very emotional,” added Moltke.

The fire started at around 7:30 am under the red-brick building’s copper roof, emergency services told reporters.

As flames and huge plumes of black smoke billowed from the rooftop, fire trucks surrounded the building, covered in scaffolding and canvas, which today houses the Danish Chamber of Commerce.

Danish rescue services said that they could not give “any guarantees” that the facade of the building could be saved.

“The facades are still standing, but they are starting to give way as the construction burns away,” director of emergency services Jakob Vedsted Andersen told reporters.

“We are trying everything we can to protect the facades, but we cannot give any guarantees,” he added.

“It’s a copper roof, and it’s simply impossible to get under that roof, so the fire has plenty of time to build intensity,” Vedsted Andersen told the Ritzau news agency.

The Borsen building, close to the Christiansborg parliament and seat of government, was commissioned by King Christian IV and built between 1619 and 1640. It is one of Copenhagen’s oldest and best known landmarks.

Housing a vast art collection, it was being renovated to celebrate its 400th anniversary.

Images from the scene showed several people carrying works of art, including a painting of the building.

Forces from the Danish military were also called to the scene, in particular to try to evacuate artworks.

Police said they had blocked off parts of the city centre as part of the fire-fighting efforts.