rescue first, obviously. when that is finished, what's the focus? >> the investigative teams come in. the first thing they will be looking at is the condition of the debris. and you really focus at the beginning in evidence that could disappear. after the search and rescue is done, there is prevailing evidence. the investigators will be interested in the way that the pancake parts are lying, the way they are broken, the configuration. it's like taking a broken jigsaw picture and put it back together. and the structure will talk to you. the trained eye of a good investigate will allow you to imagine what that configuration tells you about how the -- how it initiated and progressed, the failure. that will be a lot.