Yeah it is sad on a lot of levels. Aside from the obvious, people with PTSD often don't get treatment due to the social stigma as well as the possibility of losing or not getting certian jobs. 99.9% of people with PTSD will have no violence and most will be where you would not know if they did not tell you. But this is the perception of PTSD and vets at large, setting the mental health problems even further back.
At least 3 of the SEALs that were in Ramadi, Iraq when I was attached the 101st in Ramadi are now dead. 2 in combat and I had met (that I remember 2), this was the second. A lot of that team went, including Kyle went on to kill Bin Laden. It is just really sad.
On the same day I found out a Marine I served with and know on a much more personal level has cancer. No matter how invincible we think we are, our time is all very, very short.