People around the world have pledged more than $1 billion to rebuild Notre Dame. But according to a spokesman for the cathedral, that still might not be enough to cover it.

"We don't know if it's enough or not," Andre Finot told CBS News' Roxana Saberi. "You can say it's crazy to have a billion euros but we don't know. Maybe the cost is two or three billion."

The Paris prosecutor's office is urging people who are donating money to beware of scams. For almost every authentic effort to raise money for the cathedral's restoration, there's a crook seeking to capitalize on its devastation.

Some of the legitimate charities you can donate to include Friends of Notre Dame, The French Heritage Society, La Fondation Avenir du Patrimoine a Paris and The Basilica of the National Shrine of the Immaculate Conception.

Finot said it could take weeks to learn what caused the fire that raged for at least 12 hours and devoured the roof of Notre Dame, leaving a hole where its spire once stood.

He doesn't think it was linked to renovations taking place when the blaze broke out.

"There were too many protections on these renovations," Finot said.

According to Finot, there are also smoke detectors throughout the cathedral.

Rebuilding is likely to take years, which means ceremonies like yesterday's Good Friday procession that usually take place inside the cathedral will have to be held in its shadows.

The archbishop of Paris told worshipers commemorating the crucifixion of Jesus Christ that France is crying and the world is crying with it.

Easter Mass that was supposed to take place at Notre Dame has also been moved. It's set to take place Sunday at a church just a short walk from the cathedral.