This study analyzes the December 2014 “nut rage” incident on Korean Air Lines by means of in-depth interviews with corporate communication experts. We examine how Korean Air managed this crisis of legitimacy, asking whether its legitimization strategy and tactics were effective. The authors argue that Korean Air breached both cognitive and moral legitimacy in terms of leadership, corporate culture, internal and external communication, and legality. The results demonstrate to other organizations what types of legitimacy resources and tactics are required in order to meet social expectations in their responses to crises.