This chapter discusses the phases of disaster management and information and communication technology in early warning systems. It examines the challenges being faced by an intra-agency communication network during the response phase, and what information and communication technology services are required for such an interoperable system in developing countries. The chapter provides the world's efficient early warning systems. It focuses on the existing seismic early warning systems in place within advanced countries and in a few developing nations. Disasters are infrequent, occurring in a society that is vulnerable to Hazards like floods, hurricanes, earthquakes, and so forth. Disaster Management involves four phases: preparedness, planning, response and recovery. Interoperability of devices, communication systems and networks is the key to successful response activities. The National Task Force on Interoperability, comprising 18 national associations, bears the mandate to address issues pertaining to communications interoperability.