Over the last 25 years, rapid advancements in the development and proliferation of communications technologies has had a dramatic impact on the ways we obtain, interpret, and respond to information. This is particularly true within the context of risk and crisis communication, which has been profoundly affected by the development of mobile technologies and new media. Social media is one such technology that has (perhaps unexpectedly) influenced all facets of emergency management, particularly preparedness and response. This talk will begin with an introduction to the field of risk and crisis communication, and then will discuss the impact that social media has had on disaster preparedness and response. This talk will outline the strengths of social media for crisis communications, as well as several significant challenges that social media has posed for emergency management. Lastly, this talk will examine several case studies (Hurricane Sandy and 2011 Goderich, Ontario tornado) to set the stage for a deeper discussion about lessons learned and future directions of research and practice.