During these difficult times, these are two articles we found helpful when talking to children about violence: 

From the National Association of School Psychologists:  
http://www.nasponline.org/resources-and-publications/resources/school-safety-and-crisis/talking-to-children-about-violence-tips-for-parents-and-teachers
 
From CommonSense Media
https://www.commonsensemedia.org/blog/how-to-talk-to-kids-about-violence-crime-and-war?j=6364336&l=512_HTML&u=101507097&mid=7000332&jb=12&utm_source=032318+Teen&utm_medium=email&utm_campaign=weekly