Notre-Dame came far closer to collapsing than people knew. This is how it was saved. - The New York Times
▻https://www.nytimes.com/interactive/2019/07/16/world/europe/notre-dame.html
What became clear is just how close the cathedral came to collapsing.
The first hour was defined by that initial, critical mistake: the failure to identify the location of the fire, and by the delay that followed.
The second hour was dominated by a sense of helplessness. As people raced to the building, waves of shock and mourning for one of the world’s most beloved and recognizable buildings, amplified over social media, rippled in real time across the globe.
That Notre-Dame still stands is due solely to the enormous risks taken by firefighters in those third and fourth hours.
Disadvantaged by their late start, firefighters would rush up the 300 steps to the burning attic and then be forced to retreat. Finally, a small group of firefighters was sent directly into the flames, as a last, desperate effort to save the cathedral.
“There was a feeling that there was something bigger than life at stake,” said Ariel Weil, the mayor of the city’s Fourth Arrondissement, home to the cathedral, “and that Notre-Dame could be lost.”
The message that scrolled across the monitor was far more complicated than the mere word “Feu.”
First it gave a shorthand description of a zone — the cathedral complex was divided into four — that read “Attic Nave Sacristy.”
That was followed by a long string of letters and numbers — ZDA-110-3-15-1 — code for a specific smoke detector among more than 160 detectors and manual alarms in the complex.
Finally, came the important part: “aspirating framework” — indicating an aspirating detector in the cathedral’s attic, which was also known as the framework.
It remains unclear just how much of that entire alert the employee understood or conveyed to the guard — and whether the critical part of it was relayed at all, though Elytis insists it was.
By the time it was sorted out, the flames were already running wild, too high to be controlled by a fire extinguisher.
Finally, the guard radioed the fire security employee to call the fire department. It was 6:48, 30 minutes after the first red signal lit up the word “Feu.”
All the sensitive technology at the heart of system had been undone by a cascade of oversights and erroneous assumptions built into the planning, said Glenn Corbett, an associate professor of fire science at John Jay College of Criminal Justice in New York.
“You have a system that is known for its ability to detect very small quantities of smoke,” Mr. Corbett said. “Yet the whole outcome of it is this clumsy human response. You can spend a lot to detect a fire, but it all goes down the drain when you don’t move on it.”