Almost everyone has seen the horrific fire that claimed most of the roof and iconic spire at the Cathedral of Notre Dame on April 15, the news spreading almost as fast as the soaring flames themselves. Burning for over 15 hours, the fire seriously damaged the timber structure over the central crossing and most of the lead-covered wooden roof above the vaulted stone ceiling.
Certainly on everyone’s mind while watching was the question of how the fire could have spread so fast. By the time firefighters arrived the entire structure seemed to be engulfed in orange flames.
Completed in the year 1260 after a hundred years of labor, Notre-Dame Cathedral is considered one of the finest examples of French Gothic architecture ever made. Its innovative use of the rib vault and flying buttress system for stability and its enormous and colorful rose windows set it apart from any earlier Romanesque style of churches built in medieval Europe and it has an exciting history. In 1804, the cathedral was the site of the Coronation of Napoleon I as Emperor of France and later sprang to worldwide fame after the publication, in 1831, of Victor Hugo’s novel “The Hunchback of Notre-Dame.” The church is one of the most widely recognized symbols of the city of Paris. Approximately 12 million people make the trip to Notre-Dame annually, making it the most visited monument in that city, surpassing even the Père-Lachaise Cemetery with Jim Morrison’s grave by a factor of 10.
Over the last eight centuries the cathedral has seen numerous restoration projects, notably those in 1844 to repair damages caused by the French Revolution 50 years earlier. In 1963 the façade was washed of the centuries of soot and grime, restoring it to its original off-white color. It was during this cleaning that structural engineers had found the masonry of the cathedral’s exterior had deteriorated greatly due to increased air pollution causing erosion of decorations and discoloring the limestone. Such degradation had occurred that by the late 1980s, several gargoyles and turrets had fallen off from the damaged surface.
But not all work was preventative maintenance. In 2013, the set of four 19th-century bells atop the northern towers were melted down and recast into new bronze bells to celebrate the building’s 850th anniversary. The new acoustical designs were made to recreate the sound of the cathedral’s original bells from the 17th century.
Last year a renovation of the cathedral’s spire was begun, requiring the temporary removal of copper statues on the roof and other decorative elements. This occurred just days before last week’s fire.
At exactly 6:20 p.m. a fire alarm went off within the structure that sent guards scurrying but after a quick investigation no fire was found. By the time a second alarm sounded 23 minutes later flames were already racing across the beams in the attic, a rarely visited space above the stone structure.
The cathedral had a smoke detection system, but no other basic fire-safety measures such as ceiling sprinklers which might have helped douse or even slow the calamity. It was said that authorities for the building had decided against one years ago.
Online images displayed in stark detail how the fire ran across the roof and up the spire (which eventually toppled). The cathedral’s vaulted stone ceiling hampered firefighters from shooting water at the attic from the ground.
But why did it spread so fast? Experts say the combination of a structure that’s more than 850 years old, completely dry as a bone and built of heavy timber construction with soaring open spaces led to the quick conflagration. Many people were shocked to see that the roof of the stone church was in fact supported by an array of wood rafters. This “forest” of wooden trusses was originally procured from a 52-acre stand of oaks, each individual tree contributing to a single beam over 30 feet long. Many, it was said, dated back to the 13th century. The roofing material for the cathedral was sheet lead which quickly melted and gave an open vertical vent for the licking flames. More than 400 firefighters were engaged in the battle while another hundred worked to evacuate church artifacts.
Along with the high temperatures of the fire the molten lead raining from the top made matters worse.
Authorities say the source of the fire could have been an electrical problem or one of human error — such as a tossed cigarette. We probably will never know.