COPENHAGEN, Denmark (AP) One of Copenhagens oldest buildings is on fire and its iconic spire has collapsed.

The fire that began Tuesday in the copper roof of the 17th-century Old Stock Exchange, or Boersen, has now spread to much of the building, and parts of the roof have also collapsed, said firefighters spokesman Jakob Vedsted Andersen.

The fire was first reported at 7:30 a.m.

The extinguishing work is very difficult, said Vedsted Andersen, adding there are parts of the building the firefighters cannot enter because it is too dangerous.

The cause of the fire was not immediately known.

The building, which is situated next to the Christiansborg Palace where the parliament sits, is a popular tourist attraction. Its distinctive spire, in the shape of the tails of four dragons twined together, reached a height of 56 meters (184 feet).