Following a probe involving amateur videos and photos from locals, investigators have drawn the conclusion that the Notre Dame might have caught fire on the roof, towards the base of the iconic spire.
The investigators are also looking into two potential issues related to the conflagration, including a potential alarm system sensor deficiency and the elevators built for the construction workers.
A massive blaze broke out at the Notre Dame cathedral on Monday evening, resulting in the collapse of the building's spire and two-thirds of its roof. Firefighters, however, managed to extinguish the blaze by Tuesday morning, saving the historic building and the relics it housed.
Earlier, French media reported that investigators consider a short circuit to be the likely cause of the fire at the iconic Paris cathedral.