On April 15, 2019, the night of the great Notre-Dame fire, crowds lined the bridges and banks across the Seine, watching in sorrow and disbelief as flames devoured the cathedral’s roof, and columns of thick, dark smoke shot into the sky.

Little-noticed was a firefighting boat docked along the riverbank beneath the cathedral. Its powerful motors furiously pumped water from the depths of the river into hoses connected to mobile fire stations on land. By the time the fire was extinguished hours later, the Brigade des Sapeurs-Pompiers de Paris, the city’s fire-fighting force, estimated that half the water used in the operation had come from the Seine.

“We had before us two elements of nature, fire and water,” said three-star General Jean-Claude Gallet, commander of the Sapeurs-Pompiers, in an interview. “The fire had the face of a demon with a mind of its own. Every time we went after it, it found another attack route on its path of destruction, as if it understood our desperation. Then, right in front of us, we had the Seine. It was as if the Seine were human… It all sounds a bit mystical, but the Seine came to our rescue.”

And so it was the Seine, the life-giver of Paris, that saved the monument that sits at the city’s historic and geographic heart: Notre-Dame. Earlier that day, Paris had been enjoying one of those rare, bright April afternoons made famous in song. It was the Monday of Holy Week, and inside Notre-Dame, clerics and workers prepared for services that would culminate in Easter Sunday. Out of sight, the fire was smoldering in the high reaches of the cathedral’s attic, a frame of medieval oak tree trunks nicknamed “the forest” that supported the lead-covered roof.

The fire was so silent and cunning that when the internal fire alarm sounded at 6:20 p.m., nothing was found. About thirty minutes later, flames roared from the rafters for all to see, transforming the 850-year-old stone structure into a blazing inferno. By 8 p.m., most of the roof and the attic had collapsed. The delicate nineteenth-century spire, built with 500 tons of oak and covered in 250 tons of lead, snapped in two and crashed to the ground.

The Sapeurs-Pompiers de Paris are part of the French armed forces and trained to respond to crisis with military discipline. But nothing had prepared them for a fire of this magnitude. The water supply and water pressure from fire hydrants on land was much too weak to extinguish the fire. A break in steady water flow could have caused the hoses to explode. “The fire on the roof was the equivalent of 500 apartments or twenty tanker-trucks burning,” said General Gallet. “We absolutely had to have another water source.”

That source was the Seine. Two fire brigade boats equipped with special pumping equipment sped to the lower bank of the river near Notre-Dame. Colonel Paulin, a small fire boat, was permanently anchored on the Quai de Conti just across the river; it arrived within minutes of the first emergency alert. But it was designed to put out fires in private boats and cars, and its hydraulic capacity was much too weak.

The Île-de-France, an older but much more powerful floating fire station, was moored seven miles upstream at Joinville-le-Pont on the Marne River. The 36-foot-long boat maneuvered through a giant loop in the river before it reached the Seine, passed through a lock, and arrived about thirty minutes later. As soon as it docked beneath the cathedral, firefighters on land attached four huge hoses to it. The boat’s two turbo diesel motors began pumping and filtering water from the depths of the Seine, with the same force as a giant fire truck.

At one dramatic moment as the Sapeurs-Pompiers battled the blaze, General Gallet feared a chain reaction. Pockets of high winds, hot gases, and flame caused the fire to spread quickly inside the cathedral, weakening the stone vaulting above the nave, and reaching the northern bell tower. If the tower collapsed, the weight of the eight bronze bells within it would pull down the southern bell tower as well. The Sapeurs-Pompiers had thirty minutes – no longer – before Notre-Dame, the most visited monument in Paris, a masterpiece of medieval architecture, would fall into ruin. Twenty-five firefighters armed with hand-held hoses were ordered into the cathedral. They would either save the northern tower from within or face certain death. The firefighters managed to ascend the stairs, spraying water into the air and onto the stone walls and steadily cooling the space. It was enough to prevent the collapse of the north tower.

In the early hours of the morning, the flames were extinguished. When the world awoke, the stone structure of Notre-Dame was still standing tall. “The water of the Seine saved Notre-Dame,” General Gallet said.

I grew up Catholic, and I would never dare to contradict those who believe that God answered their prayers in saving Notre-Dame. But I also have come to believe in the spiritual as well as the physical power of the Seine. Even before the ancient Romans conquered Gaul, its source had been the site of a temple and a place of pilgrimage dedicated to Sequana, a healing goddess. Sequana was the original name of the Seine, and its waters were said to contain the power to make miracles. Pilgrims came from hundreds of miles away to pray and be cured.

Notre-Dame will be rebuilt, differently perhaps, but with its primal place in French life and its symbolic meaning for the world intact. It will be reborn as a vibrant place of music, ritual, and prayer for believers and a beautiful museum for the masses. The holy waters of the river that once bore the name Sequana saved the greatest cathedral in the world. I want to believe that the spirit of the goddess Sequana herself lives on.