From 9/11memorial.org: The attacks of 9/11 showed us the worst in people. But it was also a time when many wonderful, compassionate, and heroic deeds occurred. “Heroes” were everywhere on 9/11 and in the days afterwards. The shock and the sadness also brought people — families, friends, and strangers alike — together in a way that felt special. It is important to remind your children that we are also remembering those heroes and those times. Help your children recognize how their own compassion can prevent future acts of intolerance and violence by reminding them to express their ideas
respectfully and to treat people who are different from themselves with kindness.

http://www.911memorial.org/talking-your-children-about-911