Our soldiers die all over the world all the time in various types of accidents. Ive lost a couple of friends to accidents on military bases.
Ive never checked it out but i have a feeling that the number of non hostile fire deaths in the military is fairly high.
You are right... there have been a lot of 'rollover' car accident deaths in Iraq.
And I'd guess a 40 mph headon with an M1A1 cant be pretty for the other vehicle.
This is a sad and unfortunate incident.