Abstract: Collaboration awareness, as extension to organization awareness, is knowing how organizations do work and achieve their goals. This knowledge moves on a scale from stated prescribed ways of acting (such as procedures and protocols) to informal channels of communication, teamwork and decision-making. Based on available static and dynamic data, standardized insights can be given about collaboration in emergency situations in the form of organigraphs. We argue that for gaining practical collaboration awareness, both the formal structure of an organization as well as informal interactions should be inspected. Informal interaction includes informal communication channels, actual decision making on the spot and multi-disciplinary joint activities. We have implemented our system in the form of a web-based visualization tool. This tool would have been useful in the Hercules disaster, giving insights in informal information exchange, possibly preventing fatal decisions.