How common is post-traumatic stress disorder (PTSD) in children?

Each year over 3 million children are diagnosed with post traumatic stress disorder (PTSD). In the last few years more and more kids are experiencing such traumatic events, such as experiencing or witnessing a serious accident, natural disasters -- like a fire, flood, tornado, hurricane -- domestic abuse, gang-related violence in the community, a shooting or violent attack, sexual or physical assault, terrorism or being diagnosed with a life-threatening illness. New research shows that the death of a parent can also trigger the disorder.