Certainly we pray for the lives of those who are affected by this. But just as certainly shall we search for those who caused it and bring them to justice.
Burning a piece of paper or a book or a building does nothing to stymie the flow of ideas. Ideas are borne by people, and radical ideologies are spread via in the meeting places of these people.
The statement “we will not back down” in the face of evil is good. One cannot call cowering in the shadows a life of freedom.