We present an analysis of the narratives that emerged on Twitter during four different terror attacks. To this end, we analyze a data-set consisting of more than five million Twitter messages. We use the structural topic model (STM) approach to automatically detect six narratives of crisis. Our findings indicate that i) Twitter users are highly engaged in the dissemination of operational and memorial narratives, ii) emotions and narratives directed towards authority accounts dominate the discourse regarding the entire event, iii) the presence of positive authority nodes (i.e. authority nodes who are predominantly perceived as being positive) directly impacts the type of a discourse and fuels hopeful memorial narratives to a larger extent than accusations and blaming.