Sirens People Warn Defense World War Eslpod Civil

"Civil defense sirens" are "sirens" (things that make a loud noise as a warning to others) that are used to warn "civilians" (ordinary people who are not part of the military) about an "approaching" (going to happen soon) "danger" (something that can cause harm or death). They were first used in World War II to warn Americans about "air raids" (attacks from the air, specifically from airplanes or bombs). When Americans heard the civil defense sirens, they were supposed to run to a "bomb shelter" (a place designed to be strong enough to keep people safe during an explosion, often underground) or another safe place.

The sirens could produce a few different sounds. Some were "alerts" that were supposed to tell people to be "extra" (more than usual) "cautious" (careful). Other sounds warned people of an actual "attack" (an attempt to cause harm, damage, or death). During World War II, most of the sirens in the United States were designed to "sound" (make a noise) for a period of between three and five minutes.

Today, many of the World War II sirens have been "repurposed" (adapted for another type of use) to warn people about natural disasters. Some communities use the sirens to warn "residents" (the people who live somewhere) about dangerous "tornadoes" (very strong and very damaging windstorms) or even "tsunamis" (very large waves that cause damage to seaside towns after underwater earthquakes). Many of the sirens have been replaced by the use of the Emergency Alert System, which plays emergency messages on all local television and radio stations, as well as cell phones.