Here is a little background first from Maxime Lépante, our French correspondent in France:
1) the workers who were refurbishing the roof of Notre-Dame are among the best specialized craftsmen in the world, concerning the restauration of medieval monuments (their title is “Meilleur Ouvrier de France”).They love their work, and take all the necessary precautions. They have worked in many rooms of the Castle of Versailles, they have restored many churches and cathedrals. For example, they worked during more than 20 years on the marvelous Strasbourg cathedral (I lived in Strasbourg and saw their progress), and there was never a single problem.
2) the workers stopped at 6:00 PM, the fire started at 6:50 PM, near scaffoldings, used to climb there.
3) no electricity was allowed near the roof, because it was made in wood and as a matter of security, every inflamable thing was banned too. So, to have a fire there, someone needed to bring something.
This is an update about what we know today about the fire that destroyed the roof and parts of the vaults of Notre-Dame:
1) Restoration work hadn’t started on the roof. The scaffolding were still being put in place. The architect in chief of the “Monuments Historiques” (“Historical Monuments”, the administration that maintains and repairs monuments in France), Philippe Villeneuve, who was responsible for the refurbishing of the spire of Notre-Dame, has stated that : “Work had not started yet, scaffoldings were still being built”.
2) Everything was done to avoid any source of heat near the wood of the roof. No electrical plug, no welding were allowed. So, Philippe Villeneuve says : “The hot spot hypothesis is therefore not the right one”.
3) The head of the company that was building the scaffoldings (Europe Echafaudage) (Europe Scaffolding), Julien Le Bras, was interviewed by a French TV (BFM) : “All I can say for the time being is that at the moment of the fire, absolutely none of the employees of my company was present on site”.
4) He added : “All safety procedures on the Notre-Dame de Paris site have been respected”.
5) One of my friend sent me an email concerning the security on the roof of Notre-Dame. She has a diploma in Art history and studied in the “Ecole du Louvre” (“Louvre School”, were students learn art history and restoration processes) :“I visited the framing of Notre Dame with architects of the “Bâtiments de France” (“Buildings of France”, the highest rank for an architect in France), some years ago. This 13th century timber frame was extremely protected. Each intervention is always accompanied by historians, architects, experts; no work is envisaged without extreme caution; no source of heat, no torch, no electrical apparatus is allowed; a high-performance alarm system is in place; and very strict supervision of all people allowed there. I think we will eventually learn that this was arson.”
6) So, as I said yesterday, with all these security measures, to have a fire on the roof of Notre-Dame,someone had to bring something there, and lit it up.
For 1 and 2, see the article of “Le Monde”, reserved to the paying members, but the important parts have been copied here:
For 3 and 4, see the article of the “Journal du Dimanche”, here.