Notre Dame fire: World reaction
German Chancellor Angela Merkel and British Prime Minister Theresa May have led the world reaction to the fire that is gutting Paris' world-famous Notre Dame Cathedral.
Merkel called the cathedral a "symbol of France and our European culture".
"My thoughts are with the people of France tonight and with the emergency services who are fighting the terrible blaze at Notre-Dame Cathedral". May wrote on Twitter.
French President Emmanuel Macron cancelled a major televised speech to head to the scene.
"Our Lady of Paris (Notre-Dame de Paris) in flames. Emotion of a whole nation. Thoughts for all Catholics and for all French," he said.
"Like all our countrymen, I'm sad tonight to see this part of us burn."
US President Donald Trump said: "So horrible to watch the massive fire at Notre Dame Cathedral in Paris. Perhaps flying water tankers could be used to put it out. Must act quickly!"
I fondly remember standing outside Notre Dame with Jen almost 30 years ago. So sad to see this beautiful cathedral in flames this morning. Our thoughts are with the people of France and emergency services who are fighting this fire. They will rebuild as Parisians always do.— Scott Morrison (@ScottMorrisonMP) April 15, 2019
However, French fire authorities have discounted this idea, saying it would destroy the building.
The Vatican said the blaze had caused "shock and sadness" and said it was praying for the firefighters.
A French firefighter says the structure of the cathedral has been saved from total destruction.
PM @ScottMorrisonMP & Oppn Leader @billshortenmp should today agree to establish an Australian fund to support the restoration of Notre Dame so that Australians can show their solidarity once again with the people of France.— Malcolm Turnbull (@TurnbullMalcolm) April 15, 2019
And Paris mayor Anne Hidalgo said firefighters were optimistic they could salvage its main towers from the flames.
The cathedral, which dates back to the 12th century, is a UNESCO World Heritage site that attracts millions of tourists every year.
My heart goes out to Paris. Notre Dame is a symbol of our ability as human beings to unite for a higher purpose—to build breathtaking spaces for worship that no one person could have built on their own. I wish France strength and shared purpose as they grieve and rebuild.— Hillary Clinton (@HillaryClinton) April 15, 2019
It is a focal point for French Roman Catholics who like Christians around the world are celebrating Holy Week, marking the death and resurrection of Jesus.