The cause of the massive fire that engulfed Notre Dame Cathedral was probably accidental, Paris Prosecutor Remy Heitz said Tuesday.
The blaze burned through the night and caused extensive damage to the eight-centuries-old Gothic structure, prompting its spire to collapse.
"Nothing suggests that it was a voluntary act ... We are favoring the theory of an accident," Heitz told reporters, adding that a team of 50 people were working on a probe into how the fire started.
He said the investigation would likely be "long and complex."
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The prosecutor's office said police had started questioning construction workers who had been carrying out extensive renovations to balustrades and crumbling gargoyles at the site.
Hundreds of firefighters worked through the night to bring the fire under control. It was extinguished on Tuesday morning, some 15 hours after it broke out.
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Officials who entered the charred edifice reported that despite significant damage and some weaknesses, the building's main structure had been saved. Staff from the fire department also managed to evacuate some of the artworks from inside the cathedral, the culture ministry said.
nm/rc (Reuters, AP, AFP)