that wall makes it sobering to watch. does this look like the work of an explosive device or windows popping or something else? >> i'll tell you what, we will have to wait until we find the wreckage. that will find us for certain or actually a witness to this. in the meantime, a bomb would have the same effect. for instance, put against the skin with a particularly lethal explosive like petn would break the plane apart. a lot of the bombs are detonated by barometric switches. let's take the scenario in complete speculation, one of the people thinks he is carrying something else, gets on the airplane and puts bagging in the overhead and it reaches an altitude of let's say 35,000 feet, explodes and the plane comes apart. these bombs have been around since the 80s.