learn the identities of the americans killed, including navy medic max soviak of ohio and marines rylee mccollum of wyoming, kareem nikoui and hunter lopez of california, and david lee espinoza of texas. 18 americans also wounded in the attack, some med evaced to germany in special surgical units inside c-17 planes. but questions remain on just how this attack took place with the pentagon scrutinizing taliban check points. >> if they were able to get up to the marines at the screening, at the entry-point of the base, there was a failure somewhere. it was a failure by -- taliban operate with various degrees of competence. some of those guys are very scrupulously good, some of them are not. >> reporter: a photo from this week reveals just how dense the checkpoints can be. dozens of service members within arm's length of those trying to get in. >> this is close-up work. the breath of the person you are searching is upon you.