Parisian firefighters battled flames at the famed Notre Dame Cathedral into the night Monday, finally extinguishing the blaze after dark. The entire structure of the roof was engulfed in the fire, fueled by the massive wooden beams that held it up. Notre Dame’s iconic steeple collapsed.

The steeple had been undergoing a renovation, and part of the structure was surrounded by scaffolding. A fire alarm went off around 6:20 p.m. local time. Within hours, much of the roof was gone.

By Tuesday morning, the damage assessment was underway. Officials warned that the structure may have dangerous vulnerabilities, especially in its higher sections.

Photos taken from the panoramic roof of the Montparnasse Tower in Paris show the Notre Dame Cathedral before and after a massive fire Monday. (Thomas Samson/AP and Dan Kitwood/Getty Images)

Taken near the cathedral’s famed organ, the floor is strewn with burned debris and stones crushing several rows of pews. The roof is ripped open where the steeple once stood.

Photos taken inside Notre Dame Cathedral show the interior before and after a massive fire Monday. (Martin Bureau/AFP/Getty Images)

Photos from inside the cathedral show the high altar and the 18th-century sculpture by Nicolas Coustou depicting Jesus descending from the cross. The usually dark space is lit from above by sunlight. In the foreground, a pile of charred rubble is visible, and tall candlesticks droop inward.

Photos taken inside Notre Dame Cathedral show the heart of the monument before and after a massive fire Monday. (Ludovic Marin and Christophe Petit Tesson/AFP/Getty Images)

Speaking on French radio early Tuesday, Culture Minister Franck Riester said that many significant works of art in the cathedral were saved and that Notre Dame’s organ had survived the flames — whether it had suffered water damage was still to be determined. Riester also confirmed preliminary reports from firefighters that they had been able to save the church’s two most hallowed relics: the crown of thorns Jesus is said to have worn and a tunic worn by Saint Louis, a 13th-century French king.