||Can populations self-organize a crisis response? This is a work in progress report on Exercise 24, X24, Mexico, a follow up to the first two exercises, X24 and X24 Europe The X24 exercises used a variety of free and low-cost social media and web 2.0 tools to organize, plan, and manage local and international expertise and organizations in the response to a preset disaster scenario. The first X24 focused on Southern California, while the second X24, X24 Europe, focused on the Balkan area of Eastern Europe. These exercises involved over 12,500 participants for X24 while X24 Europe had over 49,000 participants. This paper presents an overview of the recently completed X24 Mexico exercise, as well as the preliminary results. Â© 2012 ISCRAM.