France yesterday called on architects of the world to submit ideas on a new spire for Notre-Dame after it burned in Monday's blaze, prompting debate over whether to copy the old or embrace an entirely new design.
The launch of the contest came as it transpired that firefighters lost valuable time in tackling the fire after a computer glitch sent investigators to the wrong part of the cathedral, according to French reports.
An initial fire alarm sounded at 6.20pm local time, but after failing to find a blaze security services at the landmark called it a false alarm.
At 6.43pm, a second alarm went off. Only when they returned to the upper area of the edifice did they call in firefighters, after coming across 10ft flames at the base of the spire.
According to 'Le Parisien', the computer glitch had caused the alarm to signal the wrong location.
Police are investigating the possibility that the fire was the result of a short-circuit in a restoration workers' lift.
Despite the delay, firemen were on the scene within 10 minutes.
A few more and the entire edifice would have burned to the ground in a "chain-reaction collapse", a French government official said yesterday.
The firefighters took swift action to protect wooden supports in the twin medieval bell towers, averting a bigger catastrophe, said Jose Vaz de Matos, a fire expert with France's culture ministry.
Edouard Philippe, the prime minister, yesterday launched an international architecture contest to decide how the partly 850-year-old monument should be rebuilt - a "huge and historic" undertaking that Emmanuel Macron, the president, says he wants to be completed "within five years".
The government has named Jean-Louis Georgelin, a former five-star general, to oversee the race to wind up the work before France hosts the Olympic Games in 2024.
The devastating fire burned down the Gothic masterpiece's roof, ancient wooden beams and 19th-century spire, sparking global offers of condolence and support.
Mr Philippe said: "The international contest will settle the question of whether we should build a new spire, whether we should rebuild the spire that was designed and built by (Eugene) Viollet-le-Duc, in identical fashion, or whether we should... endow Notre-Dame cathedral with a new spire adapted to the techniques and the challenges of our era."
Benjamin Mouton, Notre-Dame's former affiliated architect, said it was pointless seeking to restore a building that has already been "heavily altered, modified and reinforced". "On the other hand, we must recreate the cathedral's silhouette and rebuild the spire. That to me is indispensable," he said.
Despite the devastation, much of the cathedral, including its famed bell towers, remains intact.
To the delight of the French public, the metal cockerel that perched on the top of Notre-Dame's spire has now been retrieved in the rubble.
"It is dented but properly restorable," a ministry of culture spokesman said. Stored inside the rooster is one relic of St Denis, one of St Genevieve and one of the thorns from the crown that Jesus Christ is believed to have worn at the crucifixion. Their condition is unknown.
The rooster has served as a "spiritual lightning" rod for Notre-Dame, according to the cathedral's website.
It is not the only priceless artefact to have been rescued from the flames of Notre-Dame. Jean-Marc Fournier, a fire brigade chaplain, has been declared a hero after he rushed into the burning cathedral to rescue the Crown of Thorns and the Blessed Sacraments.
Tributes and words of support continued to stream in from around the world yesterday as the bells of cathedrals around France rang out to mark the exact moment when the fire started on Monday. (© Daily Telegraph, London)