This study expands current crisis communication research by exploring the communication of instructing information via Twitter. Drawing from the internalization, explanation, and action components of Sellnow & Sellnow's (2013) IDEA Model, this study analyzes live tweets posted by the Boston Police Department during the 2013 Boston Marathon bombing crisis. Examining Tweets posted during a crisis allows us to better understand what constitutes useful, valuable instructing information that can be communicated via social media in real time. Further, scholars have just begun exploring social media's implications for crisis communication. This study extends the IDEA Model to reach crisis communication and social media. Findings also indicate the three components of the IDEA Model are valuable topics to consider when communicating instructing information via Twitter. Finally, we learn that Twitter's 140 character limit does not impede the social media platform as a vehicle to communicate instructing information during a crisis.