After 9/11, Americans know what it is like. The fear followed by the anger: who could do such a thing? People of faith turn to pray and in the wake of the Paris attacks a Mass and vigil took place at the Notre Dame Cathedral. Here is a brief but moving CNN video of the bells tolling at Notre Dame and a memorial Mass for the victims. Americans are naturally concerned about what could happen here, but standing in solidarity with the French is a good first response to this tragedy.