What caused the Notre Dame fire?

I don't have a firm opinion on what caused the Notre Dame fire. I'll be skeptical of an official investigation/report by the French gov't since the French gov't is motivated to cover for Muslims. For the same reason, I'm skeptical of reportage by the mainstream media. Here's some interesting things I've run across, for what it's worth:

Former chief engineer of ND can't at this point see how an accidental fire could happen . "It takes a lot of kindling to set old oak on fire. We rewired the electrical system in 2010 to make it short-proof. I'm stunned." https://t.co/NGphMkVRtp

— Sam Schulman كافر| ن (@Sam_Schulman) April 16, 2019

Notre Dame fire: The owner of the restoration company - which is very highly regarded - says that absolutely none of his 12 workmen were on site when the fire began. They had already left for the day. https://t.co/9a0B7dzyMB

— Emerald Robinson (@EmeraldRobinson) April 16, 2019

#Update: WORLD EXCLUSIVE my source on the ground in #Paris says that the firefighter has said this could be "Sabotage" of one worker at the #NotreDame in #Paris. Saying police are going to interrogate every worker who worked at the scene, and those who got fired at the company.

— Sotiri Dimpinoudis ❁‏ (@sotiridi) April 16, 2019

#Update: WORLD EXCLUSIVE my source on the ground in #Paris says that the firefighter has said, it was impossible that the fire managed to spread so fast at the #NotreDame because electrical equipment or wires in the wooden space, was prohibited to be used in fear of sparks.

— Sotiri Dimpinoudis ❁‏ (@sotiridi) April 16, 2019

Says all electrical wires of the construction crew, were guided on the side of the building or the cranes if used at the time, and was not in contact with the wooden space at the #NotreDame church in #Paris. Says regulations were strictly and always followed by the company.

— Sotiri Dimpinoudis ❁‏ (@sotiridi) April 16, 2019