I went there last June, and it truly was astounding. Walking inside felt like being sent back a few centuries. I'm glad I got to see it, but I feel for those who may never get that chance now. And it was actively used for services, so unfortunately they'll need a new home.
With that said, Notre Dame has been through multiple ransackings and lootings. If a simple fire were able to fell the Dame thing it would've been gone centuries ago!