Towers

Spire

Transept

The fire was first visible in this area of the cathedral in images taken Monday evening.

Within an hour, the fire brought down the iconic spire and continued to spread along the roof.

Later, the fire burned through most of the wooden roof.

In just over an hour, a fire spread through the wooden attic of the Notre-Dame Cathedral in Paris and toppled its 300-foot spire on Monday.

Around 6:30 p.m., Paris time, smoke began to pour out of the cathedral’s roof, near scaffolding that had been put up over the last few months to conduct renovations on the spire.

Marga Abejo-Momper via Twitter

The fire started in the cathedral’s attic, said Jean-Claude Gallet, commander of the Paris firefighters.

The attic is an oddly shaped space, seldom visited, that lies above the soaring stone arches visible from the floor of old European cathedrals. Diagrams of Notre-Dame and official descriptions of the space indicate that it is crisscrossed by giant, timber trusses that add structural integrity to the cathedral.

Attic

Wood

Stone

Attic

Wood

Stone

Attic

Wood

Stone

“Once these massive timber structures start to burn, they almost never can be stopped,” said Jonathan Barnett, an international fire safety authority at Basic Expert in Australia. “We focus on their masonry walls and forget all the massive timber within.”

Each beam of the cathedral attic’s wooden frame is made from an individual tree — more than 1,300 in total — giving it the nickname “the forest.”

Notre-Dame De Paris/Maurice de Sully association

A dry space like the attic tends to accumulate dust and debris, making it even more flammable. “That’s where your risk really is,” said Andrew Tremlett, the Dean of Durham Cathedral in the United Kingdom, which has a similar wooden vaulted roof like Notre-Dame’s.

After taking over the attic, the blaze quickly spread across the roof and engulfed the spire, a wood-frame structure covered in lead.

Thibault Camus/Associated Press

Within minutes, the spire collapsed, toppling to the side before breaking off.

Ian Langsdon/EPA, via Shutterstock

Fire safety experts said houses of worship can pose special problems for firefighters. The cathedral’s wood roof, for instance, is made of a flammable material and is difficult to reach.

“These cathedrals and houses of worship are built to burn. If they weren’t houses of worship, they’d be condemned,” said Vincent Dunn, a fire consultant and former New York City fire chief.

Images taken on Tuesday showed the scale of the damage inside the cathedral.

Christophe Petit Tesson/Agence France-Presse — Getty Images

Notre-Dame is located directly in the center of the city on a small island called Île de la Cité, which may have been more difficult for firefighters and emergency workers to reach. As of 8:30 p.m., Paris time on Monday, all roads on the island were closed.

Louvre

Pompidou

Center

Paris

Seine

Île de la Cité

Pont

d'Arcole

Quai de l'Hôtel de ville

Notre-Dame

Cathedral

Quai de Montebello

Pont

Saint-Louis

Pont de

l'Archevêché

Luxembourg

Palace

PARIS

Eiffel

Tower

Notre-Dame

Cathedral

Seine

3 miles

Louvre

Notre-Dame

Cathedral

Eiffel

Tower

PARIS

Seine

Quai de l'Hôtel de ville

Île de la Cité

Notre-Dame

Cathedral

Quai de Montebello

Paris

Notre-Dame

Cathedral

Île de la Cité

PARIS

Notre-Dame

Cathedral

Paris

Seine

Paris

Île de

la Cité

Notre-Dame

Cathedral

PARIS

Seine

Notre-Dame

Cathedral

The New York Times | Sources: OpenStreetMap; aerial image by Google.

About five hundred firefighters were battling the blaze on Monday evening, according to France’s interior ministry.

Photographs from Monday showed Paris’s firefighters using compact trucks equipped with aerials to battle the blaze from up high. These nimble trucks most likely allowed the fire department to navigate the island’s narrow streets and position its equipment close to the cathedral, surrounding the building.

Benoit Moser/Paris Fire Brigade, via Associated Press (left); Stephane de Sakutin/AFP/Getty Images

At least one boat was deployed to pump large amounts of water from the river. Large-diameter hoses, about five inches wide, were connected to water-pumping trucks, which fed water to the fire trucks. The hoses effectively created water mains, supplying a large volume of water to fight the fire.

Where Firefighting Equipment Was Deployed

Approximate locations of fire trucks

Rue du Cloître-Notre-Dame

Notre-Dame

Cathedral

A fire boat

pulled water

from the Seine.

At least two trucks

were on this side.

A water-pumping

truck supplied

the fire trucks.

Seine

Where Firefighting Equipment Was Deployed

Approximate locations of fire trucks

Notre-Dame

Cathedral

A fire boat

pulled water

from the Seine.

At least two trucks

were on this side.

A water-pumping

truck supplied

the fire trucks.

Seine

Where Firefighting Equipment Was Deployed

Approximate locations of fire trucks

Notre-Dame

Cathedral

Seine

A fire boat

pulled water

from the Seine.

At least two trucks

were on this side.

A water-pumping

truck supplied

the fire trucks.

Note: Locations are based on analysis of photographs taken on Monday. ·Source: OpenStreetMap

By 11 p.m. on Monday, Gen. Jean-Claude Gallet, the Paris fire chief, said that the structure, including the two magnificent towers soaring above the skyline, had been “saved and preserved as a whole,” but that two-thirds of the roof was destroyed. The cause remained unknown.

Bertrand Guay/Agence France-Presse — Getty Images
Correction: April 16, 2019

An earlier version of a diagram with this article incorrectly labeled a portion of the cathedral as the nave.