tornado & tsunami sirens

tornado & tsunami sirensis a siren used to provide an emergency population warning to the general population of approaching danger. It is sometimes sounded again to indicate the danger has passed. Some sirens (especially within small towns) are also used to call the volunteer fire department when needed. Initially designed to warn city dwellers of air raids in World War II, they were later used to warn of nuclear attack and natural destructive weather patterns such as tornadoes and Tsunamis.