states use existing air raid sirens to warn of tornadoes and flash floods. People living near certain nuclear facilities such as the Hanford Site in Washington have special radios in their home that are set to broadcast a warning signal in the event of a radiological emergency. Some emergencies (AMBER Alerts, for instance) are also sent out via e-mail, cellphone text message, and highway signs. Many U.S. institutions of higher education now use multiple warning technologies on their campuses, including outdoor and indoor sirens, public address systems, email and cell phone text messaging, and digital displays. Prior to the adoption of the Emergency Alert System, the US used CONELRAD from 1951 to 1963 and the Emergency Broadcast System from 1963 to 1997. See also Alert Ready (Canada) Emergency Alert System (United States) Standard Emergency Warning Signal (Australia) NL-Alert (Netherlands) Emergency Mobile Alert (New Zealand) Mobile phone alerts in the United Kingdom (United Kingdom) Warning system (list of types) Prediction of volcanic activity References External links ALERT FM- - Commercially available FM radio-based emergency notification system Disaster preparedness Civil defense