In the first place, security staff at the central Paris monument wasted 35 minutes from the first alarm before they called the fire brigade.
The two officials sent to examine the roof space in the wake of the first alert from the smoke detectors went to the wrong part of the vast structure and, therefore, saw nothing.
The faithful who had been assisting at Mass were surprised by the sudden acceleration of the priest-celebrant, who was informed at 18.16 of a potential problem and told to wrap the job up in five minutes and get the people out. This was done. Calmly and without panic.
A few minutes later, at 18.21, it was announced that there had been a false alarm, and the evacuees were invited to return.
At about 18.30 the fire alarms went off again, and fragments of ash started to fall into the cathedral from the roof under the spire. This time, people needed no encouragement to leave.
A series of stupid delays
Somewhere between 18.40 and 18.50, the two officials wandering in the upper reaches finally discovered the blaze at the base of the spire. The fire brigade was finally called at 18.51.
The emergency services took less than nine minutes to reach the cathedral. But the extra delay due to the failure to correctly respond to the first alarm meant that the fire was already well-established before the fire fighters arrived.
Le Canard Enchaîné says that detectives from the criminal brigade believe an electrical short-circuit to have been the most likely cause of the disaster.
They have looked at the lift motors and electricity installations necessary for the scaffolding surrounding the spire, which was a building site at the time of the blaze. But none of that equipment is anywhere near the presumed point of the outbreak.
The investigators have spoken to the workers on the scaffolding, where smoking was strictly forbidden. Only to discover seven butts, and several confessions that smoking did, indeed, occasionally take place on the elevated site. No one was working on the site at the time of the blaze.
"The bells, the bells!"
Then there is the bizarre situation of the temporary bells.
Le Canard says that, despite a strict rule forbidding such an installation in any historical building, the roof space of Notre-Dame was home to several sets of bells, all of them activated by electric circuits which snaked through the dust and debris of the wooden superstructure.
One set was located just over the transept, that’s the bit of a church which forms the arms of the cross, so considerably further back than the presumed source of the Notre-Dame blaze.
But the other set, three bells also activated by electricity, were in the base of the spire. They were switched off in 2012, only to be put back in use at the start of the work on the main belfries in the cathedral’s two towers.
Their installation was authorised, against all safety rules, by the Regional Director of Cultural Affairs. But the agreement was purely temporary. Once the work on the main bells was completed, these three should have been switched off again, and permanently.
According to Le Canard Enchaîné, these three bells rang out on the day of the drama during the Masses at 8 o’clock, 9 and mid-day. And they also sounded, tragically for the last time, at 18.04, exactly twelve minutes before the first fire alarm went off.
Apart from the snake’s nest of wires leading to the bell installation, investigators have noted that the roots of the scaffolding around the spire were planted in the zone occupied by these wires, leading to the risk of accidental damage to the cables and other electrical equipment.
Although the fire protection plan for the cathedral included the obligation to have two state employees on permanent duty in the sacristy, there was never more than one, employed by a private security company.
And he worked from 8 in the morning till 11 at night. At which point the security of the cathedral was supervised by the concierge, from his bed.
The so-called dry risers, pipes permanently in place in every public building, which the fire brigade use to pump water to feed their hoses at higher levels, could deliver a maximum of only 500 litres per minute in Notre-Dame, totally insufficient for the blaze the fire-fighters had to face. By the time the members of the brigade had retreated to get their own high-pressure equipment . . . five times more powerful . . . the roof was already beyond saving.