N. Baloian et al. (Eds.): CRIWG 2014, LNCS 8658, pp. 311–318, 2014. © Springer International Publishing Switzerland 2014 LOST-Map: A Victim-Sourced Rescue Map of Disaster Areas André Silva 1 , Diogo Marques 1 , Carlos Duarte 1 , Maria Ana Viana-Baptista 2 , and Luís Carriço 1 1 Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal asilva@lasige.di.fc.ul.pt, {dmarques,cad,lmc}@di.fc.ul.pt 2 Instituto Português do Mar e da Atmosfera, Lisbon, Portugal mavbaptista@gmail.com Abstract. In the aftermath of natural disasters, members of the affected com- munities are often the de facto first responders. Local volunteers can respond quickly, are strongly motivated, and have the necessary ground knowledge. However, their search and rescue efforts may be misdirected in the absence of information about the location and status of victims. We propose LOST, a sys- tem that gathers data from smartphones in affected areas, even when the regular communication infrastructure fails, and aggregates it in a web interface for visualization. For each individual, LOST-Map shows location traces and activ- ity indicators. The information can be explored by selecting time-frames and/or applying filters over activity indicators. This paper briefly describes the design of LOST, introduces the visualization tool LOST-Map, and reports on a study (n=10) that suggests that it can be effectively used by untrained volunteers. Keywords: Disaster management, Emergency response, Location services. 1 Introduction When disasters (like earthquakes, hurricanes or tsunamis) hit populated areas, mem- bers of the affected communities often offer themselves to help in the field. While they may not have the necessary knowledge to provide first aid to victims in every situation, these volunteers know the geography and have a better sense of which peo- ple are missing. They can be valuable actors in emergency operations, providing im- mediate response and collecting information useful to other stake-holders, like civil defence efforts. They can report changes in the field, which people need help, etc. In areas that become isolated, local volunteers are sometimes the primary emergency responders for extended periods of time. However, when information flows are cha- otic, it is difficult, even for locals, to have an accurate account of the location and status of potential victims. Often the communication infrastructure fails or is over- loaded, hindering the dissemination of information. Technology plays a crucial role in emergency response. Yet, tools that empower local volunteers aren’t still common. LOST is a system that tackles the challenge of providing a source of actionable information to volunteer responders. With LOST,