Due care and due diligence require doing what a reasonable or prudent man would do. They do not require perfection. Without question the fire is a gut-punch, but that does not automatically mean there is negligence. Until the investigators have facts and conclusions, it probably best to go along with the presumption that it is accidental.
Of course the building will not be rebuilt as it was. Nor should it be. The important part is the resolve to rebuild and for those involved to respectfully marry tradition with state-of-the art. Notre Dame was not built in a single time and with a single design. It consists of many evolutionary changes, including some of its most iconic -- the double buttresses and the spire. This really is just another generational change in the life of the lady. Hopefully, this generation will include modern alarms with more precise trouble isolation and maybe a bit more fire-blocking.
What I have seen so far is the fire bringing humanity together. I see people praying, singing and grieving together in Paris. I see the rest of the world offering support. I see firefighters both doing their job and being heroes at the same time. I see substantial reconstruction pledges. Most of all, nobody died (although sadly 3 responders were injured). Added bonus, the most significant artifacts were rescued/survived (unlike the Brazil Museum).
