. >> alfonsi: a responsibility owed to soldiers, like 34-year- old sergeant tom bates. >> sergeant tomwere struck with a large i.e.d. it was a total devastation strike. >> alfonsi: bates miraculously walked away from this mangled humvee, one of four i.e.d. blasts he survived during deployments in iraq and afghanistan. do you remember feeling the impact in your body? >> tom bates: yes. >> alfonsi: what does that feel like? >> tom bates: just basically like getting hit by a train. >> alfonsi: and you were put back on the frontlines. >> tom bates: yes. >> alfonsi: and that was it? >> tom bates: uh-huh. >> alfonsi: when bates returned home in 2009, his wife libby immediately saw a dramatic change. >> libby bates: i thought, "something is not absolutely right here. something's going on. for him to just lay there and to sob and be so sad. you know, what do you do for that? how do i-- how do i help him? he would look at me and say, "if it wasn't for you, i would end it all right now." you know, i mean, like, what do you-- what do you do-- and what do you say to somebody who says that? you kno