civilians. a pentagon investigation said everybody died as a result of a single suicide bomber blast. but a cnn investigation now raises hard questions about whether the attack has been fully investigated. >> a full warning, this report contains graphic images and may be disturbing to some viewers. cnn's nick peyton walsh has more. >> reporter: a blast into the crowd. >> i saw a lot of hands, legs without their bodies. >> reporter: at least 170 afghans and 13 u.s. troops died after an isis suicide bomber struck outside kabul airport. the pentagon investigation of the attack released friday said everyone died in the blast. >> the single explosive device killed at least 170 afghan civilians and 13 u.s.