Why Notre-Dame Cathedral, a medieval stone church, has burned so quickly

Associated Press

Notre Dame cathedral is burning in Paris, Monday, April 15, 2019. Massive plumes of yellow brown smoke is filling the air above Notre Dame Cathedral and ash is falling on tourists and others around the island that marks the center of Paris.

• Notre-Dame Cathedral, in the heart of Paris, is on fire.
• The church took hundreds of years to build, and wooden support beams put inside in the 1200s are still there today.
• Unlike the stone towers at the front of the building, those wooden frames inside make the church flame-friendly.

Notre-Dame Cathedral, an intricately-carved gothic church that has been sitting in the heart of central Paris for more than 850 years, is on fire.

The blaze erupted late Monday afternoon, as stunned tourists and locals stood on the streets of Île de la Cité, an island in the middle of the Seine where the church is located. Many people opened their phones and filmed the bright orange flames billowing into the sky.

The two iconic stone bell towers at the front of Notre-Dame were not immediately consumed by the flames, but the roof of the church that connects those towers to the flying buttresses at the back was quickly engulfed in yellow-tinged smoke.

Construction crews had been working on a $6.8 million renovation of the church's spire. That spire, pictured below, fell to the flames around an hour after the blaze broke out. A church spokesman told French media that the medieval frame, which is like the church's skeleton, was also alight. That is not good news for the church.

AP Photo/Thibault Camus

Flames rise from Notre Dame cathedral as it burns in Paris, Monday, April 15, 2019. Massive plumes of yellow-brown smoke are filling the air above Notre Dame Cathedral and ash is falling on tourists and others around the island that marks the center of Paris.

The hulking framework of wooden beams that supports Notre-Dame is composed of huge pieces of timber tinder, ripe for catching light. The supports are even called a "forêt" (or forest), because they're enormous pieces of oak. This "charpente" or frame, was built from 1,300 oak trees, enough wood to fill more than 21 hectares of land, La Tribune reported. According to Notre-Dame de Paris, the church framing is more than 100 meters long and the beams that are burning have been standing there since the 13th century.

Even the church's website writes, almost forbodingly, that "fire is not impossible" for the gothic masterpiece that took roughly 200 years to build.

The wood framing sits under a lead roof, which weighs 210 tonnes.