When public security organizations like fire brigades deal with emergency situations, ‘real world’ problems and phenomena are inseparably intertwined with media and communication: Not only are working practices grounded in professional knowledge, discourse and interaction, but the achievement, modification, storage, distribution and selection of such organizational knowledge is also increasingly supported (or even enabled) by media technology. Against this background, the deployment of media innovations in organizations that deal with emergencies may cause additional (‘second order’) troubles and lead to an escalation of the crisis. On the basis of participatory observation and video documentation at a training center for firefighters this paper examines communicative practices in the use of “ubiquitous” media in emergency situations. Finally the findings will be summarized and discussed with regard to the concept of “ubiquitous computing”.