A massive fire broke out at the iconic Notre Dame Cathedral in the centre of the French capital on Monday.

How the fire began

On Monday evening social media users started to post footage of an intense fire engulfing the medieval Catholic cathedral, Notre Dame, which is situated in the centre of Paris. The fire reportedly began at around 6:50 pm local time, according to the Paris fire department. AFP reported that the fire may have been started accidentally during renovation work underway inside the cathedral.

A Sputnik France stream of the situation showed the fire continuing to burn out of control as of 7:45 pm local time.

Later, Parisien reported, citing the French Interior Ministry, that 400 firefighters have been deployed to put out the massive fire. Later, the French Security Service said that attempts to put out the fire with the deployment of air tankers could damage the Cathedral.

Irreplaceable loss 

The Cathedral's structure was seriously damaged by the fire. Netizens have posted a series of heartbreaking videos showing the moment the Notre Dame de Paris' famous 300 foot spire collapsed. Local media have reported that the fire has destroyed the entire roof.

Later, a Sputnik correspondent reported from the scene that the left bell tower of the iconic Notre Dame Cathedral in Paris has gone up in flames. He also added that firefighters were examining the interior of the right tower of the Cathedral.

Andre Fino, a spokesman for the cathedral, said that treasure of iconic Notre Dame cathedral are unlikely affected by the fire that swept the building, as its holy relics are kept in a sacristy.

Later, the cathedral's rector said that some holy Catholic relics have been recovered from the fire. He said that the Crown of Thorns, and the tunic of St. Louis have been rescued. He also said that several paintings were saved, adding that "some were too big" to take down.

Meanwhile, Paris’ First Deputy Mayor Emmanuel Gregoire said on Monday that he hoped the majority of relics in the burning Notre Dame cathedral can still be saved. Gregoire said firefighters, hundreds of whom were mobilized to put out the blaze, were trying to save the facade and stop the flames from spreading to the iconic main entrance.

Fire brigade chief said that he believes that the firefighters were able to save two towers of the blaze-hit cathedral. Authorities said later that massive fire destroyed two-thirds of the roof of the Cathedral.

Launch of criminal investigation into Notre Dame fire

The French Prosecutor's office has opened a criminal investigation into the fire that engulfed Notre Dame Cathedral on Monday, local media reported, citing the French Interior Ministry. Earlier, Paris police stated that it is still unclear what caused the fire or if anyone died as a result of the incident.

Reaction of local authorities and high officials

French President Emmanuel Macron expressed his condolences on Twitter.

"Notre-Dame consumed by flames. Emotion of a whole nation," French President tweeted, noting further that he was "sad to see a part of us burn this evening." He also expressed solidarity with "all Catholics and all French people."

Later, Macron and French Prime Minister Philippe arrived at the fire site.

US President Donald Trump urged French officials to "act quickly" to fight the fire. "So horrible to watch the massive fire at Notre Dame Cathedral in Paris. Perhaps flying water tankers could be used to put it out. Must act quickly!" he said.

German Chancellor Angela Merkel also reacted to the Paris fire, saying the Notre Dame Cathedral is a "Symbol of European Culture". 

UNESCO is also reported to be carefully monitoring the worrying situation at the Notre Dame Cathedral.

Vatican spokesman Alessandro Gisotti said that the Holy See was shocked by reports of a huge fire that tore through the Notre Dame cathedral in Paris on Monday.

"The Holy See has reacted with shock and grief to the news of a terrible fire that has ravaged Notre Dame de Paris, the symbol of faith in France and globally," he tweeted.