Crews fanned out in and around the cathedral and in the streets surrounding the landmark, scrubbing the pavement and rinsing the ground with chemicals, to ensure that it is safe for pedestrian traffic once again.

A French environmental protection group estimated that the fire had churned through 440 tons of lead that was in the roof and the spire. Fumes and other residue from that high amount of lead could still cause health risks, the group said. Cleanup crews were wearing haz-mat suits and taking decontamination showers, but pedestrians could still get very close to the plaza, certainly within range of any contaminants still being expelled. Paris city officials had in June done testing in surrounding neighborhoods for lead contamination and had found no cause for concern; subsequent testing in August had found unacceptable levels of lead particles in the air at two nearby schools, forcing authorities to close the schools. School was not in session.

The blaze began on April 15, consuming the iconic 300-foot spire and burning through a large amount of wood on the inside and outside of the building. Some treasures were saved by the more than 500 firefighters who battled the blaze for 15 hours, at one point risking their lives by staying inside to build a wall of water between the fire and the bell towers. Fire officials revealed that the 850-year-old cathedral was within 15 to 30 minutes from being entirely consumed. As it was, a large amount of the wooden frames inside were charred.

Much of the cathedral remained, however. The famous organ, which has 8,000 pipes, is intact. It dates to the 1730s. The cathedral's three very large rose windows are still there, as was what is thought to have been a piece of wood from the Crown of Thorns that the Bible says Jesus wore on the Cross. The cathedral was home to many more famous and irreplaceable works of art, however, and officials are already undertaking a damage assessment. Many other smaller stained glass windows already number among the artistic and architectural casualties.

Donations have poured in from around the world and will no doubt come in handy in what is certain to be an expensive, long restoration effort. French President Emmanuelle Macron announced a timeline of five years for such a feat; experts warned that it could take decades. Macron also announced an international competition to design a replacement spire.