That upper right picture especially reminds me of corium.
Another idea; a few years ago, the Washington Monument had to be closed to repair damage from an earthquake and the entire structure was covered in scaffolding. They wrapped the scaffolding in fabric and illuminated it and that itself was cool to look at (there’s a photo here). So if it’s possible to get enough scaffolding, the under-repair building can be nice looking.
I’m waiting for the design ideas to roll in that have the reconstructed roof covered in solar panels, or perhaps a cell tower incorporated into the steeple. 
That’s so creepy and cool.
Where in the roof would they be doing this?
They were working on restoring the spire.
Yeah, it’s pretty metal.
I’ll see myself out. I regret nothing.
I can’t vouch that it’s scientifically true, in fact I suspect nobody has taken a full inventory with weights and sizes, but we joke that if you put together all the bits and pieces of wood which claim to come from the Holy Cross, you’d be able to build at least five dozen crosses. There certainly were enough Spears of Roland sold at Roncesvalles to equip both sides at your choice of any Hundred Years’ War battle.
But as Shodan says, that’s really not the point.
The primary damage seems to be confined to the roof, and the total loss of the spire.
Of course there is a lot of smoke and water damage, the damage the burning roof and spire did as it fell into the building, and strictly speaking the whole site should be a red-flagged toxic waste site!
Remember that there was some 220 TONS of lead on that roof, of which most melted and a good bit would have vaporized in the heat.
But at this time, my main concern is: Did the stone structure of the building take any significant damage? I.E. is the building still structurally sound, or not? Not just the heat of the fire, but also the mechanical stress of the sudden release of the 750 TON spire collapsing, releasing the load on the supporting walls in an instant.
Stone tends to be even less forgiving than concrete for rebound stress fracturing, and even a concrete building would have suffered from such an event.
The airborne lead will have already blown downwind by now, and solid lead that’s in place is not hazardous. Removing the lead can generate dust and fumes, but you manage that by screening off the work area.
The stone was already suffering from the effects of age, weather, air pollution, and loading forces. You are correct, heat is not good for rocks. Currently, those flying buttresses are pushing the walls inward with the force they have always exerted but due to the loss of the roof there is less force counteracting that so indeed the walls are under increased stress. The spire-caused damage is putting those areas at risk. Fire/water damage had weakened part of the bell towers. Emergency bracing and shoring up of the affected areas is already underway.
So far nothing more has fallen down, I hope the workers can keep up with everything that needs attention.
Saving the art treasures of ND: How centuries of priceless treasures were saved at Notre Dame - CNN Style
One view as to how to go about rebuilding: Notre Dame: How to rebuild a Gothic masterpiece - CNN Style
Rebuilt, yes, but the floor plan - especially in the public areas - was left mostly the same.
It looks like the bees survived. In other news, I never knew that bees did not have lungs.
No insects have lungs. Lungs are a fish thing. (And some snails.)
Here’s the Onion on April 17:
Investigators Trace Cause Of Notre Dame Fire To Cathedral’s Outdated 12th-Century Electrical System
Here’s the latest theory on April 18:
\m/ (>.<) \m/
Remember about 20 years ago when they rebuilt the Statue of Liberty? That was also quite a site.
I looked into it, and the various air pollution monitoring stations in Paris officially stated they haven’t recorded notable increases in lead concentrations or fine ash particulates after the fire ; which leads experts to posit that most of it must have precipitated on the Ile de la Cité and surrounding housing quarter but don’t really know for absolutely sure yet (because the air monitoring stations are further away and there are none on the island itself).
That being said, while a quick googling reveals that the specter of lead toxicity has already been raised in fringe blogs (including one op-ed I found to have been copy/pasted by a number of other small news sites, wherein the writer claims lead vaporizes at 500°C :dubious: so make of that what you will) there doesn’t seem to be a big fear of contamination of the city at large or the downwind countryside in the pages of the major news outlets. City hall however has promised it will do all it can to protect the workers tasked with clearing the rubble (and I would assume the firefighting crew is being monitored for any signs of lead poisoning as well ?)
I’m nowhere near an expert on any of this, but lead is heavy so I wouldn’t be surprised at all if the airborne stuff dropped out of the air quickly.
Lead doesn’t vaporize at 500 C but it does give off fumes, and that might be what the guy is confused about.
I don’t have anything interesting to add. But Notre Dame is a beautiful building and I hope they take the time to rebuild it properly. I am personally in favour of using more modern and fireproof materials if it can be done in a way that looks appropriate. It seems there are so many old or historic buildings with expensive restoration and sprinkler needs which governments don’t want to pay for - like the art gallery in Rio de Janiero - and which are in many ways irreplaceable. I wish the French luck in completing this job, hopefully the stone and windows are not too damaged. But it is better to do the job well than to do it quickly just because there is an Olympics.
Absolutely. I hope we don’t read in a decade or two of all the things done hurriedly, and badly, just to meet Macron’s five-year deadline.