France is paying a day-long tribute to the Paris firefighters who saved the internationally revered Notre Dame Cathedral from collapse and rescued its treasures from a devastating fire.

President Emmanuel Macron will host the firefighters for a special gathering to share “words of thanks”, according to his office.

Senior government ministers will also take part in the event at the presidential palace in Paris.

Emmanuel Macron at the cathedral on Monday
Emmanuel Macron at the cathedral on Monday (Philippe Wojazer/AP)

Later, Paris City Hall will hold a ceremony in the firefighters’ honour, with a Bach violin concert, two giant banners strung from the monumental city headquarters and readings from Victor Hugo’s The Hunchback Of Notre Dame.

More than 400 firefighters took part in the nine-hour battle to save the 12th-century cathedral on Monday evening.

Its spire collapsed and the roof was destroyed, but its famous towers, rose windows, organ and precious artworks were saved.

No one was killed in the fire, which occurred during a mass, after firefighters and church officials speedily evacuated the building.

Among the firefighters being honoured is Paris fire brigade chaplain Jean-Marc Fournier, who helped salvage the crown of thorns believed to have been worn by Jesus at his crucifixion.

Another is Myriam Chudzinski, among the first firefighters to reach the roof as the blaze raged. Loaded with gear, they climbed hundreds of steps up a narrow spiral staircase to the top of one of the two towers. She had trained at the cathedral for just this moment.

Tackling the blaze on Monday evening
Tackling the blaze on Monday evening (Francois Mori/AP)

“We knew that the roof was burning, but we didn’t really know the intensity,” she told reporters.

“It was from upstairs that you understood that it was really dramatic. It was very hot and we had to retreat, retreat. It was spreading quickly.”

She heard a roar, but her focus was on saving the tower. She learned later that it was the sound of the spire collapsing.

Aerial view of the damage
Aerial view of the damage (Gigarama.ru/AP)

Investigators believe the fire was accidental and are questioning cathedral staff and workers who were carrying out renovations to the building before the fire broke out.

Some 40 people have been questioned and some are being quizzed again Thursday, according the Paris prosecutor’s office.

Fire officials warn that the massive cathedral remains fragile, and are removing statues above the rose windows to keep them from falling.

The building would have burned to the ground in a “chain-reaction collapse” had firefighters not moved as rapidly as they did to battle the blaze, said Jose Vaz de Matos, a fire expert with the Culture Ministry.

FIRE NotreDame
(PA Graphics)

An initial fire alert was sounded at 6.20pm as a mass was under way in the cathedral, but no fire was found. A second alarm went off at 6.43pm and the blaze was discovered on the roof.

Mr Macron wants to rebuild the cathedral within five years — in time for the 2024 Summer Olympics that Paris is hosting — but experts have questioned whether that is realistic, given the vast scale of the work.

One said the rebuilding project would easily take 15 years. More than £750 million has been pledged for the restoration.