The Sensor Web is a wireless sensor infrastructure for collecting, synthesizing, distributing, viewing, and reacting to information. While the Sensor Web is well suited to collecting data in hazardous or inhospitable locations, the system has considerable value when situational monitoring must be accomplished over an extended area. The Sensor Web can provide situational awareness in many types of applications including disaster preparedness and recovery, emergency response, health and safety, infrastructure protection, homeland security, and national defense. Uses of the Sensor Web are virtually limitless since different types of sensors can be connected to the system for different functionalities. Here, the primary application focus will be that related to emergency services and rescue operations. Actual deployments will also be discussed.