Lets get a thread going looking into the fire and investigate what happened. I have attached a good diagram of a floor plan. Since the roof was clad with lead its unlikely it could have been started from the top. More than likely the fire was started in the clesestory or attic area. Access was from the bell tower area there are stairwells located near the main entrance in the buttresses. I dont think the entire roof would have burned like that if, for example, only the spire caught fire. All it would have taken was a few water bottles of gasoline well placed, with a lit cigarette in a matchbook to act as a detonator.
could someone have acessed it from the street? From the bell towers?perhaps some enterprising jihadi somehow climbed up the scaffold after work hours discreetly.
who was working on site during that day? if the likliest source of the fire is the attic the perp must have known how to access the area. normally john q pulbic cannot just walk into those areas.
could the perp have gained access to the building as a tourist and broke away from the group? Who is going in and out of there and how many people? what kind of security/restrictions were in place the day of? could someone have stowed away in the attic earlier in the day and set the blaze
what kind of device was used? surely this building did not just burst into flames it must have been set. old as the wood is i doubt a cigarette alone would have been enough, and to burn the roof so completely
facing growing financial strain, and a nightmare of a restoration task, could the people who care for the church have set the blaze as an insurance scam? Im sure they will collect insurance payout in addition to the billion already promised from philanthropists. Not only that they have turned growing apathy into an outpouring of support. Perhaps these people knew the wooden roof would burn but the stone vault was strong enough to protect the actual stone frame of the structure.
Obviously we have all heard the theories about macron orchestrating this as a flase flag to save his presidency. Not outside the real of possibility and he may have acted in concert with the curators of the church since they both really "got what they wanted" out of this
If i was an investiagator my top suspects rn would be