The fire at Notre Dame in the late afternoon of April 15, 2019 came as a shock to the whole world. The fire broke out at around 6:20 pm. The central spire, added in the 19th century by architect Viollet-Leduc, collapsed into the nave at 8pm, live on most prime-time TV news. The French were stunned. And the rest of the world learns of it during the night and the following day.
The situation before the fire
Notre-Dame de Paris Cathedral, built between the 12th and 14th centuries on the Île de la Cité in the heart of Paris, had been restored in the 19th century. Until now, it had never been affected by fire, although church fires were commonplace before the invention of lightning rods in the 18th century.
Administrative negligence and irresponsibility are also to blame. In 2016, Paolo Vannucci, professor of mechanical engineering at the University of Versailles, conducted a study for the CNRS on the risk of fire at Notre-Dame-de-Paris, particularly in the event of a terrorist attack. His report, which pointed to the need to remedy the almost total absence of fire protection systems on the roof, was classified “Confidentiel-Défense” by Manuel Valls’ government on the grounds that it contained information likely to inspire arsonists. Despite discussions between the authors of the study and the CNRS, the report was not used. Also approached, the Paris City Council indicated that Notre-Dame de Paris was not under its jurisdiction.
For several months, part of the monument had been undergoing restoration work, in particular to clean the exterior of the spire and a set of metal sculptures, oxidized and blackened by pollution. To enable this restoration work to be carried out, an imposing outdoor scaffolding structure was being erected, along with platforms and other structures in the spire’s attic. The external scaffolding was served by two elevators located 45 and 65 metres from the spire.
April 15, 2019 : Notre Dame in fire !
The fire broke out on Monday, April 15, 2019, at around 6:20 pm. It originated in the framework at the base of the spire, designed by the architect Viollet-le-Duc and made of 500 tons of wood and 250 tons of lead. The 93-metre high spire is located at the crossing of the transept. According to the fire department, the flames started in the scaffolding installed on the roof and spread extremely quickly, reaching the entire roof and destroying the framework. This was the oldest roof structure in Paris, for the nave and transept sections. It was made from 1,300 oak trees, representing 21 hectares of forest.
Incidents in the early stages of the fire
According to information from Paris public prosecutor Rémy Heitz, the first fire alarm went off at 6:18 p.m., five minutes after Canon Jean-Pierre Caveau had begun mass. This was followed by an initial first doubt, which was reported as negative after checking.
This initial alarm was triggered by the automatic activation of one of the cathedral’s smoke detectors. A security employee then went into the attic of the building, but failed to notice any fire or incident, which could lead to the hypothesis of a human error during the alarm. According to the New York Times, a misinterpretation of the alarm messages or a communication fault may have led the security employee to go to the sacristy attic instead of the nave.
Meanwhile, the fire alarm began to sound in the cathedral, interspersed with messages in French and English, urging all visitors and worshippers in the building to remain calm and evacuate as quickly as possible. Believing it to be a false alarm or a malfunction in the fire safety system (SSI), those present stayed put for a few minutes before evacuating the cathedral through the central portal, while staff left via the sacristy.
A little later, at 6:50 p.m., a second alarm sounded, this time triggered by the activation of a fire alarm button in the cathedral. A new evacuation was ordered, followed by a second verification that the fire had started in the roof structure.
Notre Dame in fire : the fire department response
The nearest fire station (Poissy) was alerted at 6:51 p m. The first fire engine arrived on the scene at 6:58 p.m., while some 30 other engines were activated simultaneously. The firefighters then set off on foot up the cathedral’s staircases to reach the roof structure, and set up their hoses inside it and on the cornices, in an attempt to halt the spread of the fire. The cathedral is not equipped with “dry columns”, which would have greatly facilitated their initial intervention.
Spread of the fire
Shortly after the second fire alarm, at 6:50 p.m., heavy smoke and flames emanating from the work area began to spread from the roof. The first firefighters arrived on the scene at 6.58pm. Numerous witnesses watch the scene from the cathedral’s outskirts.
At 7.50pm, the cathedral’s spire (500 tons of oak and 250 tons of lead plates) collapsed before the eyes of passers-by and the media. The fire gradually diminished in intensity, despite the occasional silent flare-up which suddenly doubled the height of the flames, releasing a voluminous plume of yellow smoke visible from several kilometers outside Paris. Shortly after 9 p.m., the fire regained its intensity and reached the cathedral’s north tower.
Four hundred firefighters and eighteen water hoses were mobilized. At around 10.50 p.m., General Jean-Claude Gallet, commander of the Paris fire department, announced that the towers had been saved, as the firefighters had been able to stop the fire spreading to the north tower. At 9.50 a.m. the following day, he reported that the fire had been completely extinguished. In all, the fire had lasted fifteen hours.
Causes of the Notre Dame fire
The Notre-Dame fire prompted an in-depth investigation into its causes. A number of possible causes were quickly identified, although criminal activity was quickly ruled out. Investigations focused on accidental faults, linked to renovation work in progress at the time of the incident.
Renovation work under way
At the time of the fire, Notre-Dame was in the midst of restoration work, mainly on the spire and roof. This restoration, which began in 2018, was aimed at strengthening the cathedral’s aging elements and repairing damage caused by time and pollution. The spire, in particular, had shown signs of weakness, leading to the installation of extensive scaffolding around it.
The work also concerned the wooden framework, nicknamed “the forest” because of the large number of oak beams it contained. This framework dated back to the Middle Ages and was one of the oldest parts of the cathedral. However, it was precisely in this area that the fire started, pointing investigators towards a possible cause linked to the renovation work.
Electrical fault
Among the initial hypotheses, one of the possible causes of the fire was linked to an electrical malfunction. Temporary installations, such as site elevators, had been installed to facilitate work around the spire, and an electrical short-circuit could have triggered the fire. However, this hypothesis, although considered, has never been confirmed with certainty.
On April 23, 2019, Marianne magazine published online information revealed the same day by Le Canard enchainé: bells installed in 2007 and 2012 above the choir and in the spire had been electrified, “in absolute contradiction with all the rules on these old buildings”. They were used for the last time on April 15, to ring at 6 p.m., just a few minutes before the fire broke out.
However, expert in the construction sector, who said: “The fire could not have started from a short-circuit, from a simple one-off incident. You need a real heat load to start a fire like this. Oak is a particularly resistant wood”. Craftsmen familiar with the cathedral came to the same conclusion: “The timber was as hard as stone, centuries old”.
A poorly extinguished cigarette
Another hypothesis investigated by the investigators was that one of the workers on the site had put out a cigarette incorrectly. Although this possibility was raised, the companies in charge of the work had stated that their employees had received strict instructions not to smoke on the site.
Despite numerous hypotheses, the investigation into the exact cause of the fire has not yet reached a definitive conclusion. However, it is generally accepted that the fire was caused accidentally and spread rapidly due to the old, flammable materials present in the structure. The investigation, entrusted to the Paris public prosecutor’s office, is still ongoing in 2024. The workers involved in the restoration have been questioned, but have not been held responsible.
Resources deployed to fight the Notre Dame in fire
The fire generated an enormous maximum power estimated at 2,500 MW. These estimates are based on oak combustion values of 17.5 MJ/kg, with the 1000 T framework consumed in half in 1 hour, giving a total of 1800 MW. Compare this with well-known apartment fires, which rarely exceed 2 to 5 MW, and with the calculation bases for road tunnels of 30 MW for a lorry and a tank full of petrol of 200 MW. To evacuate this energy, a standard 500 L/min fire hose can theoretically absorb 20 MW (by heating up and vaporizing all the water). This would have required 120 perfectly efficient hoses to bring the fire under control. Firefighters were only able to deploy 18 of them.
Inside the nave, firefighters used a water-launching robot (Colossus from Shark Robotics), a five-hundred-kilogram crawler that can carry two hundred meters of hose and deliver three thousand liters of water per minute.
The fire is fought from inside the towers, not from the outside. This French technique avoids pushing hot gases back into the tower and limits the rise in temperature. The absence of dry columns in the building reduced the effectiveness of the firefighters’ response from the outset. Only the north rose window will be cooled from the outside using a large ladder.
Aerial drones are used by the police to fly over the cathedral and spot fire starts. An operational drawing is also drawn up to identify the different sources of the fire and the best way to control it, as well as the strategy to adopt.
Critics raised the question of not using Canadairs planes for forest fires. This solution was rejected from the outset, for fear of causing the more structurally-supported walls to collapse under the masses of water. What’s more, the Canadairs are based in the south of France, in Nîmes, and it would have taken several hours before they were operational in Paris.
On April 16, at around 4 a.m., Lieutenant-Colonel Gabriel Plus, spokesman for the Paris fire department, announced that the fire was under control and partially extinguished. At 9 a.m., the fire was completely out.
The spread of the fire in Notre Dame
Once ignited, the fire spread rapidly through the wooden framework, a veritable labyrinth of oak beams. The 800-year-old structure served as ideal fuel, allowing the flames to spread with astonishing speed. In the space of a few minutes, the fire engulfed a large part of the roof.
The collapse of Notre Dame’s central spire
One of the most striking moments of the fire, captured live by numerous media outlets, was the collapse of the cathedral’s spire. The spire, designed by architect Eugène Viollet-le-Duc during the 19th-century restoration, was a centerpiece of Notre-Dame’s skyline. The 93-metre-high spire collapsed after being consumed by flames, sending shockwaves around the world.
The collapse of the spire was a turning point in the progress of the fire, as it allowed the flames to engulf the interior of the cathedral, threatening the rest of the structure.
The fire department’s efforts
The Paris fire department played a crucial role in preventing the fire from turning into an even greater catastrophe. Quickly on the scene, they had to cope with extremely difficult conditions, with flames reaching very high temperatures and the fire spreading rapidly upwards. Their priority was to save the two emblematic towers on the west façade, as well as the artistic and religious treasures inside the cathedral.
Thanks to their intervention, the two towers, which support Notre-Dame’s monumental bells, were preserved, as were the main façade and numerous works of art. However, the firefight lasted several hours, and it was not until the end of the night that the blaze was completely brought under control.
No casualties during the fire
The fire caused no civilian casualties. However, one injured firefighter was taken to hospital. Other casualties included the first firefighters from the Paris fire department (BSPP) who responded to the scene at the start of the fire. These were medical cases of gas and smoke poisoning. In the end, fewer than ten people were treated by the emergency services.
Damage to Notre Dame building
The cathedral’s spire collapsed during the fire at 7.50pm. It consisted of a 500-tonne timber frame, covered with 250 tonnes of lead sheeting (oxidized on the surface). At the temperature of the fire, the lead melted and was partially vaporized (transition to the gas phase) at a boiling point of 1749°C.
Two-thirds of the roof itself, including the oak framework, sont alors en feu. This framework, dating back to the cathedral’s construction in the early 13th century for the nave and the 12th century for the chevet, was destroyed. Part of the vaulting is also affected. According to a CNRS engineer familiar with the cathedral, the structure’s resistance to high winds and storms is severely compromised.
The two towers, the architectural structure and the stained glass windows from the 12th and 13th centuries and the rose windows have been preserved. Several other, more recent stained glass windows have suffered significant damage, including the two small rosettes in the transept gables.
The north gable of the transept, weakened and unstable, had to be reinforced and secured to prevent it from falling inside the monument, risking further damage.
The fire on April 15, 2019 caused extensive damage, but fortunately the overall structure of Notre-Dame was saved. One of the biggest areas of fire damage was to the roof of Notre-Dame, which was almost completely destroyed. The lead roof, which covered the wooden frame, melted under the intense heat. The roof, dating back to the 13th century, had been one of the cathedral’s symbols, visible from miles around.
The wooden framework, nicknamed “the forest” due to the massive quantity of beams required for its construction, was also completely destroyed. This framework was one of the oldest parts of Notre-Dame, and its loss is considered irreparable from a historical point of view, although reconstruction is envisaged.
Cathedral furniture and works – Damage inside the cathedral
Despite the violence of the fire, the interior of Notre-Dame was relatively unscathed thanks to the efforts of the firefighters. Many of the works of art, sculptures and liturgical objects were saved or protected from the flames and water used to extinguish the fire.
Among the most precious works was the Crown of Thorns, a religious artifact of immense importance to Catholics. The French Ministry of Culture has announced that most of the cathedral’s treasures, such as the Holy Crown and the shirt of Saint Louis, have been saved. This was also the case for other relics and several works of art: a fragment of the True Cross and a Passion nail, as well as all the works kept in the so-called “treasure” section, including Jean Jouvenet’s Visitation and Nicolas Coustou’s large Pietà.
However, parts of the interior were damaged by debris and water, notably the main altar, which suffered damage when the spire collapsed through the nave vault.
The stained glass windows and rosettes was one of the main concerns at the time of the fire. Notre-Dame’s famous rosettes, the huge 13th-century circular stained-glass windows on the cathedral’s north, south and west facades survived the fire. However, some more recent stained glass windows were damaged by the heat and will need to be restored.
The international press hails the decisive role played by Abbé Jean-Marc Fournier, chaplain to the Paris fire department, on his role to save the tresor of Notre Dame. By chance, the sixteen copper statues (the twelve apostles and the four tetramorphs symbolizing the evangelists) installed by Viollet-le-Duc at the base of the spire, had just been removed from the site on April 11, 2019, to be transferred to the Dordogne, to Socra, a company specializing in the restoration of works of art.
The 14th-century Virgin and Child sculpture, known as Notre Dame de Paris and located at the foot of the south-east pillar of the transept crossing, was simply wetted by the fire hoses. The paintings hanging in the cathedral were not damaged.
The great Cavaillé-Coll organ of 1868, temporarily rendered unusable by soot and dust (it will have to be dismantled from top to bottom). A priori, it was saved by the stone roof slab linking the two towers.
The choir organ didn’t burn down either, and the pipes didn’t melt, but it did take on water. Johann Vexo, choir organist at Notre-Dame for fifteen years, was playing in the cathedral when the alarm sounded at around 6.30pm.
The ten large bells in the two towers do not appear to have suffered, although the belfries (wooden structures) supporting them were damaged by the fire, particularly in the north tower.
The most important damage under the spire
On the other hand, the three small bells in the attic and the three on the spire (including the “chapter” bell) were lost in the fire, as was everything below the spire.
At the top of the spire was a weather vane topped by a rooster. This contained three relics: a piece of the crown of thorns, a relic of Saint Denis and another of Saint Geneviève. The cockerel was to be removed from the spire when the scaffolding reached its summit in June 2019, and transferred to Socra in the Dordogne for restoration. Initially thought lost, the rooster was found the day after the disaster in the nave without being seriously damaged.
The modern altar, depicting the stylized silhouettes of the four Evangelists, commissioned from artist Jean Touret by Cardinal Jean-Marie Lustiger in 1989, was crushed by a pile of stones and beams burnt during the fire. The traditional Pieta altar (high altar) at the back of the choir was spared, as was its large gilded wooden cross.
At the base of the spire stood a large Collin clock dating from 1867. It was destroyed by fire, with only a few remnants found among the rubble of the spire. Unlike the frame, Notre-Dame’s clock has never been digitized, and no plans seem to be available. However, the discovery of a clock at the Eglise de la Sainte-Trinité in Paris, identical in every respect (same model, same workshops, built in the same year), should enable the Notre-Dame clock to be rebuilt identically.
The environment and pollution
White to yellowish smoke, highly opaque, was visible for miles around durinf the fire. In addition to the 250 tonnes of lead covering the spire, 210 tonnes of lead from the roof tiles were spread over the rest of the structure. To avert the risk of poisoning, nearby homes were evacuated.
According to Airparif (Air quality observatory in Paris Region) readings taken on April 16, meteorological conditions were “particularly dispersive, with an east-south-easterly wind at 3 m/s” (and a boundary layer at an altitude of 1.2 km), channelling the plume into the Seine corridor on the Parisian side of the river, thus preventing the pollution from stagnating. “Most of the pollution plume seems to have been transported out of Paris, as the five air quality monitoring stations closest to the fire did not record any increase in fine particles, nor did the sensors further away.
Witnesses who were nearby at the outset nevertheless described the air as unbreathable, or a strong smell of burning, when the flames began to be visible on the roof. Airparif does not rule out very local pollution.
The three beehives installed on the sacristy roof in 2013 were spared, and the 200,000 bees they house survived the fire. On the other hand, it is uncertain whether the two kestrels nesting on the cathedral’s north transept will be able to reproduce successfully.
However, on April 27, a prefectoral communiqué recommended that homes and other premises near the cathedral be cleaned with wet wipes. On July 18, 2019, the Agence régionale de santé (ARS) revealed very high lead levels (up to 1,300,000 μg/m2, or 1.3 g/m2) on the forecourt, in the sandy strips and surrounding public gardens, and in the courtyard of the rue Saint-Benoît school complex. From August 7, the City of Paris began a clean-up operation using a lead-absorbing gel to be applied to the contaminated soil, then removed three days after drying.
At the end of July 2020, a study based on the analysis of thirty-six samples of honey from beehives collected in July (three months after the fire), showed that, to the west of Paris (under the smoke plume), the closer you are to the fire, the more lead the honey contains: 0.08 micrograms per gram in a beehive located less than five kilometers west of the cathedral, compared with the average level before the fire: 0.009 micrograms of lead per gram.
Religious life
Until September 2019, Sunday masses and other diocesan ceremonies usually celebrated at Notre-Dame will be held at Saint-Sulpice. From the start of the new school year, Saint-Germain-l’Auxerrois will host the cathedral’s liturgy, with Saint-Sulpice hosting only extraordinary ceremonies, such as episcopal and priestly ordinations and the state funeral of former president Jacques Chirac.
After the fire
On the evening of the fire, the French were in disarray, as were many others around the world, waiting to see what would happen next. What would become of Notre Dame? A few days later, the opening of donations open for Notre Dame amounted to almost 900 M€. After some hesitation and surveys of the local population, it was decided to rebuild the building as is. President Macron has set the goal of reopening Notre Dame de Paris in 2024, the year of the Paris Olympics.
