Individuals, companies and institutions have so far donated or pledged 845 million euros, about $950 million, to the cause.

But the spectacle of French billionaires trying to outdo one another with gifts that may win them tax breaks quickly intensified resentments over inequality that have flared during the Yellow Vest movement.

The investigation: Witnesses are still being interviewed to determine the cause of the fire.

But it is clear that fundamental safeguards — like firewalls or a sprinkler system — were absent by choice, to avoid altering the cathedral’s design or heightening the risk by introducing electrical wiring to “the forest,” the network of ancient wooden beams that supported the roof.

See for yourself: Our interactive graphic takes you inside Notre-Dame’s attic, where the fire started.