Disaster rescue is one of the most serious social issues, which involves very large numbers of heterogeneous agents in the hostile environment. The intention of the RoboCup-Rescue project is to promote research and development in this socially significant domain by creating a standard simulator and forum for researchers and practitioners. While the rescue domain intuitively appealing as large-scale multi-agent domains, it has not yet given through analysis on its domain characteristics. In this paper, we present detailed analysis on the task domain and elucidate characteristics necessary for multi-agent systems for this domain.