who? >> especially when you hear this report, colonel, that la david johnson may have been left behind. give us some sense of context how that happens. we know the motto no man left behind. what can happen in situations like this? what do you have? >> chris, a firefight is something unlike anything else in human experience. it's scary. it's hot. it's dangerous. there's screaming. there's blood. it is a terrible event. and i can see how in this confusion someone can be separated. now, this happens. there is intense pressure. there is 50 enemy forces bearing down on the smaller force of u.s. and the troops from niger. they were overwhelmed. they drove directly into an ambush, a kill sack. that is the worst possible situation you can find yourself in. with the pressure being so hard, with the confusion being so intense, someone can get separated. we have a motto no left behind.