Abstract: Over the last couple of years social networks have become very popular and part of our daily lives. With the emergence of powerful smartphones and cheap data rates social media can now be accessed anytime and anywhere. Obviously, it makes sense to also facilitate social media for crisis management and response. In this contribution we present a system design for emergency support based on mobile social media with an emphasis on increasing security during large public events. We follow the design science approach as we provide an artifact design along with a description of its implementation and evaluate our artifact using the simulation study methodology. As a result of this study we gained valuable insight into how the users interact with our system and obtained information on how to improve it. Overall the users were quite satisfied with the perceived usefulness and the perceived ease of use of our system.