Paris Remembers Attack Victims at Notre Dame Cathedral

People gather outside of Notre Dame cathedral ahead of a ceremony in memory of the victims of the terrorist attacks in Paris on Nov. 15, 2015.

The Archbishop of Paris, Andre Vingt-Trois says mass at the Notre Dame Cathedral in Paris on Nov. 15, 2015.

Paris mayor Anne Hidalgo and Deputy-Mayor Bruno Julliard attend a ceremony in memory of the victims of the terrorist attacks at Notre Dame cathedral in Paris on Nov. 15, 2015.

Former French President Valery Giscard d'Estaing arrives to attend mass at the Notre Dame Cathedral in Paris on Nov. 15, 2015.

Prelates arrive to celebrate a mass in homage to the victims of the Paris attacks at the Notre Dame cathedral in Paris on Nov. 15, 2015.

People gather outside for a national service for the victims of the terror attack at Notre Dame cathedral in Paris on Nov. 15, 2015.