The pixelbar had just had a safety inspection (as much as the whole space) and its kind of an irony that it burned down after that was passed.
The general problem was that not the Hackerspace itself burned down but the building around it. There is lots of media coverage on that https://www.flashphoto.nl/nieuws/13281/zeer-grote-uitslaande... gives an idea.
There were lots of small companies in that space that worked in various areas. It is unknown where the fire broke out and given that the building is now taken down it is unlikely that we ever find out. Noone got hurt which is the most important part.
I wrote a bit about the fire and the follow up at https://milliways.social/@mcfly/110620505067543759 if you want to be updated.