An image taken from a television screen shows an aerial view of the Notre-Dame Cathedral engulfed in flames on April 15, 2019, in the French capital Paris. - A huge fire swept through the roof of the famed Notre-Dame Cathedral in central Paris on April 15, 2019, sending flames and huge clouds of grey smoke billowing into the sky. The flames and smoke plumed from the spire and roof of the gothic cathedral, visited by millions of people a year. A spokesman for the cathedral told AFP that the wooden structure supporting the roof was being gutted by the blaze. (Photo by STRINGER / AFP) (Photo credit should read STRINGER/AFP/Getty Images)
Fire at Notre Dame Cathedral
Smoke rises around the alter in front of the cross inside the Notre-Dame Cathedral as the fire continues to burn on April 16, 2019 in the French capital Paris. - A huge fire swept through the roof of the famed Notre-Dame Cathedral in central Paris on April 15, 2019, sending flames and huge clouds of grey smoke billowing into the sky. The flames and smoke plumed from the spire and roof of the gothic cathedral, visited by millions of people a year. A spokesman for the cathedral told AFP that the wooden structure supporting the roof was being gutted by the blaze. (Photo by PHILIPPE WOJAZER / POOL / AFP) (Photo credit should read PHILIPPE WOJAZER/AFP/Getty Images)
Fire at Notre Dame Cathedral
Flames and smoke billow around the gargoyles decorating the roof and sides of the Notre-Dame Cathedral in Paris on April 15, 2019. - A huge fire swept through the roof of the famed Notre-Dame Cathedral in central Paris on April 15, 2019, sending flames and huge clouds of grey smoke billowing into the sky. The flames and smoke plumed from the spire and roof of the gothic cathedral, visited by millions of people a year. A spokesman for the cathedral told AFP that the wooden structure supporting the roof was being gutted by the blaze. (Photo by THOMAS SAMSON / AFP) (Photo credit should read THOMAS SAMSON/AFP/Getty Images)
Fire at Notre Dame Cathedral
Smoke billows as flames destroy the roof of the landmark Notre-Dame Cathedral in central Paris on April 15, 2019. - A major fire broke out at the landmark Notre-Dame Cathedral in central Paris sending flames and huge clouds of grey smoke billowing into the sky, the fire service said. The flames and smoke plumed from the spire and roof of the gothic cathedral, visited by millions of people a year, where renovations are currently underway. (Photo by FRANCOIS GUILLOT / AFP) (Photo credit should read FRANCOIS GUILLOT/AFP/Getty Images)
Fire at Notre Dame Cathedral
TOPSHOT - Flames and smoke are seen billowing from the roof at Notre-Dame Cathedral in Paris on April 15, 2019. - A fire broke out at the landmark Notre-Dame Cathedral in central Paris, potentially involving renovation works being carried out at the site, the fire service said.Images posted on social media showed flames and huge clouds of smoke billowing above the roof of the gothic cathedral, the most visited historic monument in Europe. (Photo by Patrick ANIDJAR / AFP) (Photo credit should read PATRICK ANIDJAR/AFP/Getty Images)
Fire at Notre Dame Cathedral
Firefighters douse flames billowing from the roof at Notre-Dame Cathedral in Paris on April 15, 2019. - A fire broke out at the landmark Notre-Dame Cathedral in central Paris, potentially involving renovation works being carried out at the site, the fire service said. (Photo by Thomas SAMSON / AFP) (Photo credit should read THOMAS SAMSON/AFP/Getty Images)
Fire at Notre Dame Cathedral
People kneel on the pavement as they pray outside watching flames engulf Notre-Dame Cathedral in Paris on April 15, 2019. - A colossal fire swept through the famed Notre-Dame Cathedral in central Paris on April 15, 2019, causing a spire to collapse and raising fears over the future of the nearly millenium old building and its precious artworks. The fire, which began in the early evening, sent flames and huge clouds of grey smoke billowing into the Paris sky as stunned Parisians and tourists watched on in sheer horror. (Photo by ERIC FEFERBERG / AFP) (Photo credit should read ERIC FEFERBERG/AFP/Getty Images)
Fire at Notre Dame Cathedral
Crowds look on as flames and smoke billow from the roof at Notre-Dame Cathedral in Paris on April 15, 2019. - A fire broke out at the landmark Notre-Dame Cathedral in central Paris, potentially involving renovation works being carried out at the site, the fire service said.Images posted on social media showed flames and huge clouds of smoke billowing above the roof of the gothic cathedral, the most visited historic monument in Europe. (Photo by ERIC FEFERBERG / AFP) (Photo credit should read ERIC FEFERBERG/AFP/Getty Images)
Fire at Notre Dame Cathedral
The steeple engulfed in flames collapses as the roof of the Notre-Dame de Paris Cathedral burns on April 15, 2019 in Paris. - A colossal fire swept through the famed Notre-Dame Cathedral in central Paris on April 15, 2019, causing a spire to collapse and raising fears over the future of the nearly millenium old building and its precious artworks. The fire, which began in the early evening, sent flames and huge clouds of grey smoke billowing into the Paris sky as stunned Parisians and tourists watched on in sheer horror. (Photo by Geoffroy VAN DER HASSELT / AFP) (Photo credit should read GEOFFROY VAN DER HASSELT/AFP/Getty Images)
Fire at Notre Dame Cathedral
A firefighter uses a hose to douse flames and smoke billowing from the roof at Notre-Dame Cathedral in Paris on April 15, 2019. - A fire broke out at the landmark Notre-Dame Cathedral in central Paris, potentially involving renovation works being carried out at the site, the fire service said.Images posted on social media showed flames and huge clouds of smoke billowing above the roof of the gothic cathedral, the most visited historic monument in Europe. (Photo by GEOFFROY VAN DER HASSELT / AFP) (Photo credit should read GEOFFROY VAN DER HASSELT/AFP/Getty Images)
Fire at Notre Dame Cathedral
Flames and smoke are seen billowing from the roof at Notre-Dame Cathedral in Paris on April 15, 2019. - A huge fire swept through the roof of the famed Notre-Dame Cathedral in central Paris on April 15, 2019, sending flames and huge clouds of grey smoke billowing into the sky. The flames and smoke plumed from the spire and roof of the gothic cathedral, visited by millions of people a year. A spokesman for the cathedral told AFP that the wooden structure supporting the roof was being gutted by the blaze. (Photo by THOMAS SAMSON / AFP) (Photo credit should read THOMAS SAMSON/AFP/Getty Images)
Fire at Notre Dame Cathedral
People watch as smoke and flames rising during a fire at the landmark Notre-Dame Cathedral in central Paris on April 15, 2019. - A huge fire swept through the roof of the famed Notre-Dame Cathedral in central Paris on April 15, 2019, sending flames and huge clouds of grey smoke billowing into the sky. The flames and smoke plumed from the spire and roof of the gothic cathedral, visited by millions of people a year. A spokesman for the cathedral told AFP that the wooden structure supporting the roof was being gutted by the blaze. (Photo by THOMAS SAMSON / AFP) (Photo credit should read THOMAS SAMSON/AFP/Getty Images)