ITV News understands that there were people working on the roof of the National Library of Wales today, when the fire started.
Nobody is thought to have been injured.
More top news
Well that seems to be it in terms of significant snow for the time being, but it's time now for the big freeze.
Dani Rowe has announced her intention to switch allegiances from England to Wales at the Commonwealth Games.
Swansea West MP Geraint Davies will try to change the law so that the UK cannot leave the European Union without a second referendum