History

The examples and perspective in this section deal primarily with the United States and do not represent a worldwide view of the subject. You may improve this section, discuss the issue on the talk page, or create a new section, as appropriate. (June 2018) (Learn how and when to remove this template message)

With the growth of populations and the evolution of technology, the methods for communicating emergency situations have also changed, as has the definition for what might constitute an “emergency.” These methods would also very likely depend on a particular region's culture and location, as well.

Early systemsedit

In America's formative years, common means of emergency communications may have mostly consisted of church bells being rung or messengers on horseback. Later, as technology developed, the telegraph became a nearly instant method of communicating. From there, radio communications, telephones and sirens became commonplace.

After the surprise attack on Pearl Harbor, by the Japanese in 1941, Civil Defense sirens became popular and resulted in their widespread use in military bases and towns across America. A particular weakness of these systems is that they largely lack the ability to inform people what they should do.

Fire alarm systems were first developed around the late 1800s and other related life-safety detectors associated with those systems (e.g., duct detectors, heat detectors, etc.) were developed around the early 1900s. These constitute the first automated systems used in public and private buildings that are in normal and widespread use today. These systems, although originally designed for fire, have also been used for many other types of emergencies, sometimes effectively and sometimes not. For instance, if a fire alarm has been activated (as a general warning device) during an active shooter incident, the typical reaction to evacuate may not be the safest course of action; instead, a shelter in place action may be better. As an example, during the 2012 Aurora, Colorado shooting, a mass shooting event that happened at the Century 16 movie theater in Aurora, Colorado, the assailant began targeting victims as they attempted to exit the theater; in which case, it would have been unwise to heed the fire alarm, that was sounding, and evacuate.

Modern systemsedit

Today, modern communication tools such as smartphones, flat-panel digital signage, GPS, and text-to-speech (among many others) are changing the way in which people are notified about emergencies. Of added value, with these more modern tools, is the ability to provide more specific instructions. Now, instead of merely notifying people about an emergency, it is possible to provide specific instructions on what to do in order to mitigate the effects of an emergency. Furthermore, those instructions might even be customized for those peoples' specific and unique circumstances. For example, smart-phones may have geo-location abilities that would allow a map to be shown of safe locations (and perhaps routing there-to), relative to those devices' specific users — all with a singular alert being sent as the source of those warnings. Modern implementations directed at personal devices allow for acknowledgement of receipt. This way emergency services can gain insight on message reception and tally users that have reached safety.