Notre Dame de Paris is one of the most visited sites in France (Credit: Jose Losada/Flickr/CC-BY- SA2.0)

No visit to the beautiful city of Paris, France is complete without a visit to the Notre Dame de Paris or, as it is commonly called, Notre Dame. The medieval cathedral, built over 180 years ‚ÄĒ from 1163 to 1345‚ÄĒ is one of the world's most stunning examples of Gothic architecture. Unfortunately, on April 15, 2019, the 850-year-old monument, which is visited by over 13 million people annually, was engulfed in a massive blaze that caused widespread damage to the iconic structure.

The initial fire alert sounded at 6:20 pm local time, just as the evening Mass was getting underway. "Everyone was immobilized by shock for maybe a minute," said Johann Vexo, the cathedral's organist. Though there appeared to be no sign of a fire, church officials erred on the side of caution and instantly evacuated the few hundred worshippers and tourists inside. As it turned out, they made the right decision.

The devastating fire took over twelve hours to extinguish and destroyed the Cathedral's roof (Credit: LeLaisserPasserA38/creative CC BY-SA 4.0)

When the second alarm went off twenty-three minutes later, at 6:43 pm, the flames were visible. Thousands of passersby watched in horror as the fire, fueled by the lattice of ancient timber, began devouring Notre Dame's rooftop. It took hundreds of firefighters, who worked through the night, over 12 hours to extinguish the devastating blaze. By the time the fire was fully contained in the early hours of Tuesday, April 16, 2019, most of the cathedral's ceiling, as well as its iconic 250 ton lead-clad wooden spire ‚ÄĒ which had proudly stood 93 meters (300 feet) above the roof for centuries ‚ÄĒ had collapsed.

Fortunately, thanks to prompt action by Paris fire brigade chaplin Jean-Marc Fournier, the cathedral's "most precious and most venerated relic" ‚ÄĒ the Crown of Thorns, believed to have been worn by Jesus Christ on the cross ‚ÄĒ was safely removed. Church officials, firefighters, and municipal workers formed a human chain to whisk out other invaluable treasures, such as gilded candlesticks, artworks, and furnishings, and load them onto awaiting police cars. The cathedral's famous 18th-century organ, which boasts more than 8,000 pipes, and its three massive circular rose-stained glass windows that date back to the 13th century, also survived the inferno.

Notre Dame's Great Organ, built in the 13th century, is the largest organ in France (Credit: Frédéric Deschamps /Wikipedia Commons/public domain)

The cause of the fire, believed to be accidental and a result of the cathedral's ongoing renovations, is still being investigated. Meanwhile, donations to help restore the beloved structure are pouring in from individuals and corporations worldwide at an unprecedented rate, reaching almost $1 billion within just two days after the catastrophic blaze. While French President Emmanuel Macron is optimistic the cathedral will be ready to welcome visitors by the Paris 2024 Summer Olympics, experts believe it will take a lot longer to restore the 850-year-old structure.

John Fidler, former conservation director of English Heritage, a government agency that maintains England‚Äôs national monuments, told the Los Angeles Times, " The first order of business is to dry the cathedral out." While that may sound easy enough, the expert believes it could take months or years to remove all the water poured by the firefighters to douse the fire. ‚ÄúIt‚Äôs easy to make the surface dry because there are large pores on the surface, but deeper in the stone, the pores grow narrower, and it‚Äôs more difficult to suck that water out,‚ÄĚ he said. ‚ÄúWhen the walls remain damp, you get mildew and mold and fungus and salt crystallization, which can rupture the pores in the stone and cause it to deteriorate on the surface.‚ÄĚ

The cathedral's South Rose Window, constructed in 1260, depicts several biblical images including various scenes from the Old and New Testament (Credit: Nan Palmero/

The soot covering the cathedral's scorched walls poses another challenge. According to Rosa Lowinger, a Los Angeles-based conservator of buildings and sculpture, while scrubbing the walls may seem like the logical soution, it would result in even more damage. That's because the soap and water would push the soot further into the building's porous limestone walls. She believes the only effective way to remove the soot is when it is dry.

Prior to starting reconstruction, engineers will also have to assess Notre Dame's structural condition ‚ÄĒ are its walls strong enough to withstand a new roof and if so, what is the maximum weight they will be able to bear? Given that most analysis methods are designed for modern buildings, not ancient stone structures, experts may have a harder time determining the cathedral's stability.

The biggest challenge to restoring this eight-century-old beloved monument, of course, will be the design of the reconstruction. As Meredith Cohen, UCLA art historian and an expert on the Gothic architecture of Paris, succinctly puts it, ‚ÄúShould you fake history or create something of our time?‚ÄĚ Cohen believes that debate could delay the revival of the Notre Dame further. Hopefully, experts will be able to surpass all the issues and restore the cherished cathedral in a timely manner.