Smoke billows from the Notre Dame Cathedral after a fire broke out, in Paris, France, April 15, 2019.

Smoke billows as fire engulfs the spire of Notre Dame Cathedral in Paris, France April 15, 2019.

Sparks fill the air as Paris Fire brigade members spray water to extinguish flames as the Notre Dame Cathedral burns in Paris, France, April 15, 2019.

Smoke rises around the altar in front of the cross inside the Notre Dame Cathedral as a fire continues to burn in Paris, France, April 16, 2019.

Paris Fire brigade members spray water onto the facade of the Notre Dame Cathedral during the visit by French President Emmanuel Macron (not pictured) in Paris, France, April 15, 2019.

Smoke billows as fire engulfs the spire of Notre Dame Cathedral in Paris, France April 15, 2019.

Smoke billows from Notre Dame Cathedral after a fire broke out, in Paris, France April 15, 2019.

Fire fighters douse flames of the burning Notre Dame Cathedral in Paris, France April 15, 2019.

Fire fighters douse flames of the burning Notre Dame Cathedral in Paris, France April 15, 2019.

Paris Fire brigade members are seen at an entrance that looks into the Notre Dame Cathedral as a fire continues to burn in Paris, France, April 15, 2019.

French President Emmanuel Macron and his wife Brigitte walk outside the Notre Dame Cathedral where a fire continues to burn in Paris, France, April 16, 2019.

Smoke rises around the altar in front of the cross inside the Notre Dame Cathedral as a fire continues to burn in Paris, France, April 16, 2019.

Smoke billows as fire engulfs the spire of Notre Dame Cathedral in Paris, France April 15, 2019.

Smoke billows as fire engulfs the spire of Notre Dame Cathedral in Paris, France April 15, 2019.

People watch as fire fighters douse flames of the burning Notre Dame Cathedral in Paris, France April 15, 2019.

French President Emmanuel Macron and Prime Minister Edouard Philippe react as they watch the fire at the Notre Dame Cathedral as its burns in Paris, France, April 15, 2019.

Sparks fill the air as Paris Fire brigade members spray water to extinguish flames as the Notre Dame Cathedral burns in Paris, France, April 15, 2019.

Smoke billows as fire engulfs the spire of Notre Dame Cathedral in Paris, France April 15, 2019.

Flames and smoke are seen as the interior continues to burn inside the Notre Dame Cathedral in Paris, France, April 16, 2019.

Smoke billows from Notre Dame Cathedral after a fire broke out, in Paris, France April 15, 2019.

Smoke billows as fire engulfs the spire of Notre Dame Cathedral in Paris, France April 15, 2019.

Sparks and flames are seen through a destroyed stained glass window as the Notre Dame Cathedral burns in Paris, France, April 15, 2019.

A woman prays next to Notre Dame Cathedral after it suffered heavy damage from a fire, in Paris, France April 15, 2019.

People look at Notre Dame Cathedral after it suffered heavy damage from a fire in Paris, France April 15, 2019.