All three women are Muslims.
Even if French investigators found that one of the construction workers was an ardent, deranged, radical Islamist, admitted that he set an incendiary device, had the materials in his home, confessed and wanted recognition as the jihadist who destroyed Notre Dame, the French would cover up the very inconvenient truth. It would not go well with the prevailing politically correct narrative.
When you commit cultural suicide, the icons of your civilization tend to disappear.