Notre Dame cathedral is burning in Paris, Monday, April 15, 2019. Massive plumes of yellow brown smoke is filling the air above Notre Dame Cathedral and ash is falling on tourists and others around the island that marks the center of Paris. (AP Photo/Lori Hinant)

Flames rise from Notre Dame cathedral as it burns in Paris, Monday, April 15, 2019. Massive plumes of yellow brown smoke is filling the air above Notre Dame Cathedral and ash is falling on tourists and others around the island that marks the center of Paris. (AP Photo/Thibault Camus)

Notre Dame cathedral is burning in Paris, Monday, April 15, 2019. Massive plumes of yellow brown smoke is filling the air above Notre Dame Cathedral and ash is falling on tourists and others around the island that marks the center of Paris. (AP Photo)

Plumes of smoke rises from Notre Dame cathedral burning in Paris, Monday, April 15, 2019. Massive plumes of smoke fills the air above Notre Dame Cathedral and ash is reported to be falling on tourists and others around the island that marks the center of Paris. (AP Photo)

Flames rise from Notre Dame cathedral as it burns in Paris, Monday, April 15, 2019. Massive plumes of yellow brown smoke is filling the air above Notre Dame Cathedral and ash is falling on tourists and others around the island that marks the center of Paris. (AP Photo/Thibault Camus)

Flames rise from Notre Dame cathedral as it burns in Paris, Monday, April 15, 2019. Massive plumes of yellow brown smoke is filling the air above Notre Dame Cathedral and ash is falling on tourists and others around the island that marks the center of Paris. (AP Photo/Thibault Camus)