Notre Dame cathedral was “15 to 30 minutes” away from complete destruction, French authorities revealed Tuesday.

It took more than 12 hours for firefighters to extinguish the flames raging inside the Gothic gem — but the structure would have been completely reduced to cinders had it taken any longer, officials said.

“They saved the edifice, but it all came down to 15 to 30 minutes,” said junior Interior Minister Laurent Nunez, according to The Guardian.

The 850-year-old cathedral’s spire and roof were decimated. Its iconic twin bell towers remained intact.

Building specialists and architects are still trying to determine if what remains is structurally sound enough to enter.

“We have identified some vulnerabilities … notably in the vault and the north transept pinion that needs securing,” Nunez said.

Authorities consider the blaze an accident, possibly stemming from restoration work being conducted on the cathedral.