Notre Dame cathedral has been in existence for centuries and only now has been subjected to fire.
It is as Dr Alf has said, important to understand what happened and the cause or causes, without idle speculation or rumour mongering on Twitter and other social media platforms.
Structures of this sort of antiquity contain a lot of dry wood, in Notre Dame’s case 250 tons of it, thus once fire takes hold, there is all the fuel necessary for a massive conflagration.
To aid the process of understanding, the timeline and exact sequence of events will have to be established with forensic precision, so that a template can be developed to ensure that future fire risks are minimised in historic buildings everywhere in France and everywhere in the world.
Assuming the fire was caused by an accident, or carelessness on the part of workmen, contractors engaged in repair work or by a rat gnawing through nearby electricity cables(this happens in countries like America where termites are the cause), then risk management procedures have to be formulated to minimise the possibility of any recurrence.
The discovery and investigation process must be rapid and thorough so as to dispel rabble rousing, media speculation, hatred ,talk of Satanism, troublesome Muslims and lurid causes. Provided this is done, the opportunity for firebrands and malcontents to turn the fire into a Reichstag style catalytic event will be eliminated. As this is going on and the root causes found, the process of rebuilding starting with the selection of architects and detailed planning can begin once the money pledged so far is fully secured.
Leaving matters too long, dragging out the investigation, obfuscating and looking for scapegoats is politically destabilising for a troubled France and will be potentially destabilising for a Europe, which has lost its way and needs to get back on track.
One can only hope that matters proceed quickly in a spirit of hope and dynamism.