In light of incidents like the Virginia Tech massacre, there is growing need for scholarship on emergency management in higher education. Traditional literature has typically focused on locating breakdowns, blame, and accountability by questioning whether emergency responses evidence departures from protocol. Yet, experience teaches that adhering to formal protocols can sometimes backfire, and departing from these protocols can be beneficial. Indeed, changes to protocol are normal occurrences in university emergency response. To gain greater insight into the issue, the correct question is not "whether" departures occur but "why". Accordingly, this study draws upon Feldman and Pentland's (2003) illustration of flexible work routines to develop a conceptual model. In this view, routines are comprised of ostensive (written protocols and shared understandings) and performative (lived experience) characteristics. When a discrepancy between the two occurs--when enacted emergency response breaks from protocol--it signals a change in the routine. The trigger for this change is sensemaking, or the process by which organizational actors simultaneously interpret and enact responses to an evolving event characterized by temporal constraints, uncertainty, and ambiguity (Weick, 1999). This study addresses the research question: What sensemaking dynamics trigger change in university emergency response routines? It reflects a year-long organizational ethnography of emergency response in a residential life department at one urban university. Qualitative coding is used to label, organize, and analyze the ethnographic data. Thereafter, the study employs theoretical sampling to identify four embedded case studies: a committed suicide, an attempted suicide, anticipated problems by campus guests during an annual football game weekend, and disruptive celebrations following Obama's presidential election. Ostensive-performative mapping and qualitative coding elaborate the sensemaking dynamics triggering change in 12 related subroutines. The study finds three sensemaking dynamics relevant to university emergency response: Retrospect, Identity, and Plausibility. While entry-level administrators employ retrospect drawn from simulations and stories, idealized hero identities, and plausible images driven by closeness to the student experience; veteran administrators draw upon lived experiences, parent identities, and plausible images grounded in reflection. The ongoing negotiation of these dynamics provides checks and balances within the department and strengthens the university's capacity for accommodating its emergency landscape. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]