Social media has changed the way information is sought and collected. Everyone has potential to influence others through social media. Therefore, social media is used increasingly in crisis communication. Crisis managers must be able to identify warning signs and enact effective strategic responses faster and more accurately. However, research on social media in crisis communication is mostly focusing on how management and public relations forces use social media to respond to a crisis. In most research, stakeholders, media and general audiences are neglected. This paper examines the use of social media by those other publics during crisis, through a case study of Danlait’s milk crisis in 2013, to evaluate the importance of social media in crisis communication in Vietnam, and to understand what factors contributed to the becoming of a social media crisis in Vietnam.