The terrorist attack in Norway on 22 July 2011, carried out by a right-wing extremist, was a shocking event, leaving 77 dead and dozens seriously wounded. It soon gave rise to a range of interpretations and explanations as to the causes and implications of the attack. Engaging with classical anthropological and more recent sociological literature on trust and blame, the article shows that there was no hegemonic narrative or explanation of the attack, and similarly no broad agreement over the steps to be taken in order to reduce the chances of future attacks. Six different attempts to account for the terrorist attack are described, but only two correctly identify demographic change, migration and the rise of xenophobic politics as the underlying causes of the terrorist attack. This suggests that the high level of trust characteristic of Norwegian society is likely to be reduced as a result of accelerating change and accompanying social fragmentation.