Most of us will always remember the moment on 15 April when we heard that Notre Dame was on fire.

I was in my kitchen, when something unusual caught the corner of my eye. I turned towards the window to see huge clouds of smoke billowing in the spring breeze. I live on the Left Bank, with a view of the southern flank of the cathedral. I ran outside, on to the Quai de la Tournelle, where throngs of tourists and Parisians had already gathered. It was just after 7pm and the fire had only been discovered 20 minutes earlier.

Of those moments, I remember a kaleidoscope of images and feelings: the stupor in people’s eyes, their mouths forming in silent screams, the vivid yellow of the smoke. On the Seine below me, a bateau-mouche river cruise glided along the water, its passengers standing up, as if suffering an electric shock, their heads bent towards the sky. The flames were bright red and orange like those tongues of fire in Renaissance paintings. Notre Dame was in mortal danger – that much was obvious to everyone. The moment was strangely superb and yet terrible. I ran home, and cried.

We need certitudes in life. They are the frameworks of our existence, the reasons we can endure hardship and survive traumas. Notre Dame was one of them. If Notre Dame, 850 years of history, can go up in flames in just a few hours, if Notre Dame can be destroyed, then everything can disappear: democracy, peace, fraternity.

The fire was spreading so fast, the spire now engulfed in flames, it was just a question of time before it collapsed. Below my window, I could see the police trying to contain the ever-growing crowd spilling into the small streets leading to the river banks.

Firefighters appeared from every corner with gigantic water hoses. They were focused, their gestures precise and purposeful while the rest of us felt utterly powerless, rooted to the ground, our eyes fixed on Her. In the crowd, I saw a young woman staring at Notre Dame’s towers. I could see her lips move in rhythm. I first I thought she was silently praying, then I realised she was repeating the same word: “résiste, résiste, résiste … ”

Parisians kneel in prayer as the ‘soul of the nation’ burns. Photograph: Yoan Valat/EPA

Firefighters were now battling the flames approaching the north tower. They had been unable to save the timber roof made of a thousand oak beams dating back to the 13th century, but it was essential that they saved the towers or the worst would be guaranteed. The risk of total collapse was real. I told myself that if the 350 year old bourdon bell Emmanuel, weighing 13 tonnes, was to crash down from the south tower … and I couldn’t finish my own train of thoughts. It was too painful to contemplate.

President Macron, the prime minister, Édouard Philippe, and the mayor of Paris, Anne Hidalgo, had also rushed to the scene. Like the rest of us who watched horrified as the fire played out on television, they could only watch the Paris sky slowly turn dark blue while the medieval stones took on a purple tinge from the fire.

As dawn broke, she appeared, hurt yet magnificent. Our certitude in life had been shaken but had finally prevailed

Then Macron walked towards the cameras to announce that the fire in the north tower had been vanquished, that the structure of Notre Dame was safe. His voice faltered when he said: “We will rebuild Notre Dame; we will rebuild.”

Throughout the night, the crowd ebbed and flowed to her bedside. I was there, binoculars in hand, inspecting her injuries, and watching firefighters still at work, cooling her down. Bird songs rose as dawn broke in pink hues over the Seine. And she appeared, still standing, hurt yet magnificent. Our certitude in life had been shaken but had finally prevailed.

The raw emotion pouring from all corners of the world towards the heart of Paris that night is easy to understand: Notre Dame is far more than a cathedral, a place of worship for Catholics and a beautiful monument whose stained glass dates back to 1260. Notre Dame is kilometre-zero of France, one of mankind’s greatest architectural achievements, the face of civilisation and the soul of a nation.

Victor Hugo made her a world heroine, romantic and secular, a place of communion for everyone, whether a believer or not, whether a Christian or not. This is where secularism meets the sacred. Notre Dame and her 850 years of history have survived wars and revolutions, and even the stupidity and carelessness of men. Her beauty is of the kind one never gets used to. The wonder of the first gaze is a renewed miracle. Each glance carries the potency of the first.

Now the battle to rebuild Notre Dame has started and promises to be fierce. The embers seem still warm, but my unruly and angry compatriots are already dividing us into the daring and the timid, those who want to add a touch of 21st-century genius to her, and those who just want her back as she was. There is a Corbusier lurking inside every French citizen, just itching to be radical and destroy the past to create a luminous future. There is also a Bonaparte in there, wanting to redesign, reform, and dazzle the world. But there are many of us who also just want life and beauty to be preserved from our irrepressible rebellious urges.

I must admit to having felt a certain excitement at the thought of a glass roof or a modernist spire. I couldn’t help it. But does our 21st-century genius really measure up to Notre Dame’s medieval builders? Are we that arrogant to think we can add to her magnificence and rebuild something, as Macron declared, “even more beautiful”?

The battle has only just begun. The stakes are high, our responsibility to history immense. She will be watching. We must get it right.