Photos: Fire engulfs Notre Dame Cathedral in Paris

A photo from Aleks Maksimovic captures smoke billowing from the Notre Dame cathedral.
A passerby captures a photo of smoke billowing from the Notre Dame cathedral
Smoke billows from the Notre Dame cathedral in the distance.
A photo captures the famed Notre Dame cathedral on fire.
Smoke billows from the Notre Dame cathedral in the distance.
Smoke billows from the Notre Dame cathedral in the distance.
Birds fly away from the Notre Dame cathedral as flames reach the rooftop.
Cameron Mitchell told CNN: "My roommate told me to come see it. I'm not sure when it started. I'm really not sure what to think. It's tremendously sad to see this happening to such an iconic monument. The fire has been slowly spreading across the roof. I'm really not sure what to make of this yet"