Emergency alert system Emergency alert system

The post-fire entryway of the Anova school, which was located in Santa Rosa's Luther Burbank Center for the Arts. Adam Grossberg/KQED hide caption

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Adam Grossberg/KQED

The Blue Alert, a new kind of public emergency notification was named after two New York Police Department officers, Rafael Ramos and Wenjian Liu, who were killed in an ambush attack by a man who hours earlier had shot a woman near Baltimore. Spencer Platt/Getty Images hide caption

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Spencer Platt/Getty Images

This emergency alert jolted New Yorkers on Sept. 19 as police sought a suspect in connection with explosions in the New York City metropolitan area. Lacking a photo or a link to one, it raised concerns about racial profiling. AP hide caption

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AP