CHAMPS-SUR-MARNE, France (AP) — The golden angel once glimmered majestically from Notre Dame's vault.
Now, with a broken nose, chipped gold-leaf and a smashed bust, it stares up blankly at a warehouse roof in the outskirts of Paris where blackened fragments of the famed cathedral's stained glass mingle with organ pipes and jagged vault stones.
Scientists at the French government's Historical Monuments Research Laboratory are using these objects as clues in an urgent and vital task: Working out how to safely restore the beloved Paris cathedral and identify what perils remain inside the monument in a race against the clock.
Debris is still falling from Notre Dame's roof as fears over dust poisoning from the cathedral's burnt-out lead roof has frightened the people of Paris and a spring 2020 deadline looms for a major diagnostic report on how to fix the lab's most famous patient.
"For the moment, the cathedral is in an emergency state of peril... It's still falling, stones fall regularly," said Aline Magnien, the lab director. "Fifteen to 20 (scientists) have been working at Notre Dame, notably to filter out the rubble. Everything that fell from the roof vaults — the wood, the metal, the stone — has been the object of a sort of archaeological excavation."
The April 15 inferno has turned the lab in the sleepy town of Champs-sur-Marne into a hive of activity, with geologists, microbiologists and experts in metal and stained glass manning laser beams, microscopes and state-of-the-art computer technology to analyze key pieces of debris — work that goes on often until midnight.
One key question the scientists are trying to establish is how damaged the remaining stone is, after being not only burnt but then doused in water from firefighters.
Architects need to know how strong the stone is to know how heavy the cathedral's new roof and spire can be — without risking further calamity.
The lab's stone expert, Jean-Didier Mertz, proudly showed off his myriad machines, glass atriums and vault stones wrapped in kitchen cling-film. He said Notre Dame's stone could have been weakened by up to 50% because of water that caused it to expand in a close-knit stone structure that has little natural breathing room.
Although Notre Dame's two medieval towers were spared from collapsing in the fire that destroyed the cathedral's roof and spire, he warned that the stone in the French Gothic masterpiece is still not out of danger.
"Since the construction and (architect) Viollet-le-Duc's revamp in 1864, the stones haven't seen a single drop of water," he explained. "The fact there was the fire and water to extinguish it totally changed the material's surface."
Even though debris is still falling down at the cathedral, Mertz said he did not think the remaining stone structure would come down.
"If the stone was going to collapse, it would have collapsed already. But it does need serious help," he added.