and as barbara starr mentioned that was one of the wake-up calls. the question is could that plan come to fruition on a flight going to the u.s. and has that technology improved since that attempt? >> ever since the attempted bombing of that airliner in somalia in february 2016 there's been concern that al qaeda or one of its affiliates would replicate that attack on a western passenger jet somewhere. that's not materialized yet, but there's been a significant concern about that given the sophistication of that device. one of the things we're learning, and this comes from our colleague robyn kriel is that that device was taken through an x-ray checkpoint by two airport workers, insiders who'd been recruited by the al qaeda affiliates in somalia. actually went through the x-ray machine and they handed it off to a third man, the suicide bomber, who brought it onto the plane. it then exploded. fortunately, didn't blow the whole aircraft up. but the investigators actually