Investigators are saying it could take weeks to determine what caused the fire at Notre Dame Cathedral, but it appears an electrical short-circuit might be to blame. They haven't ruled anything out, but arson does not seem likely.
Why aren’t they more sure? Investigators are limited in doing their job because some areas of the site are still not safe. The building remains fragile because of the damage to the roof, which doubled as support for some of the walls.
What we know for certain are that there were renovations underway at the cathedral when the fire broke out. Officials say the two companies were engaged in work, but neither had employees on the site at the time the fire started.
Source: The Guardian