burning wreckage. this is the first 777 we've got on the ground, the first crash. oddly, the malaysian airplane before also crashed, but we haven't found the wreckage. these younger airplanes, more modern airplanes are more and more composite, and they burn. they come down in smaller pieces and they burn. what you look for in a shoot-down or an explosion is the condition of the metal. are there shrapnel holes? are there holes, entry wounds where something went through the air frame? are there bends in the metal characteristics of explosion? make some diagnosis if in fact you don't think that the u.s. satellite data was conclusive. >> is there a concern of tampering? i asked richard about the scene being contaminated. is there a concern about tampering at the site? >> well, i suppose some evidence could disappear. tampering would be a slightly different question.