Prime Minister Lee Hsien Loong on Tuesday morning expressed his sadness at the tragedy of a blaze that hit the Notre Dame Cathedral in Paris in the evening of Apr. 15, 2019.

"Deeply saddened"

In a Facebook post, Lee wrote that the 850-year-old cathedral is "part of the heritage of mankind":

"The Notre-Dame has stood witness to events in Paris and Europe for more than 850 years. It is part of the heritage of mankind, an expression of the religious faith and human spirit of generations of people who conceived it, built it, and worshipped in it."

He added that he shares the "sense of loss" of the French people:

"I share the sense of loss of the French people over the damage to their national monument and the treasures it contained."

This is his Facebook post:

Fire started in cathedral attic

The fire reportedly broke out on Tuesday, Apr. 16 at around 12:30am (Singapore time).

According to French site The Local, the fire started in the attic of the cathedral and spread quickly through the building.

A spokesperson for the cathedral said that a fire alarm went off almost immediately and staff recognised the situation quickly because they had a fire drill days before.

View this post on Instagram

Devastating to see one of the most loved cathedrals in the world being destroyed in front of our eyes today. A true symbol of Paris 😢 🔥 🇫🇷 Video by @gl0be_trotter

A post shared by EARTH FOCUS (@earthfocus) on Apr 15, 2019 at 2:58pm PDT

Spire and roof collapsed

According to The BBC, the spire and roof collapsed but the main structure, including the two bell towers, remained intact.

La flèche de #NotreDame, en flammes, s'effondre https://t.co/1zqzJ3gzCu pic.twitter.com/Tw7dD8U6Y3

— Paris Match (@ParisMatch) April 15, 2019

Aside from the cathedral's structure, many of its artworks and relics were also in danger of being burnt or damaged by smoke or falling materials.

About 500 firefighters were mobilised to neutralise the fire as other teams tried to salvage the artwork inside.

It took over four hours before the fire brigade confirmed that the main structure was "saved and preserved".

The New York Times reported that the fate of many sculptures, paintings, stained glass windows and relics "remain unclear", although a relic of the crown of thorns believed to have been worn by Jesus Christ at his crucifixion — one of the cathedral's most famous relics — was saved from the fire.

According to Anne Hidalgo, the mayor of Paris, most of the cathedral's artworks were safely removed from the building.

French Culture Minister Franck Riester also tweeted photos of them being loaded into trucks:

Thankfully, according to various reports, 16 famous statues of the 12 Apostles and the four evangelists were removed from the cathedral last week to be cleaned. Dozens of religious relics were also saved, according to Fox 5.

Fire possibly linked to renovation works

The Guardian reported that the fire could be linked to renovation works at the cathedral, although the authorities are still investigating its cause.

The cathedral had been undergoing intense restoration work at that time and many sections of the church were covered in scaffolding.

However, French media reported that there wasn't any work being done at the time of the blaze because the workers had finished for the day.

"At this moment we don't know how the fire started. There shouldn't have been any workmen on the site because they stop between 5pm and 5:30pm," a spokesperson for the cathedral told The Local.

Thousands gather to pray, sing

In response to the fire, various churches in Paris rang their bells while thousands gathered around the cathedral to sing hymns and say prayers:

https://twitter.com/OusamaBinGharib/status/1117934876731121664

By the way, in case you were wondering, here's a 360-photo of the interior of the grand icon: