emergency situation. one of the other things, of course, is pressurization issues. if you have a high altitude pressurization problem, catastrophic decompression, the time of useful consciousness in the 20,000 to 30,000 foot range is a matter of seconds. while crews are trained to deal with these emergency situations, these rapid decompressions or explosive decompression situations, again it's all a matter of timing. and similar to a -- where he was flying the crew passed out because of oxygen deprivation. so there's a lot of possible scenario. but to speculate as to which one is the likely with this amount of information is definitely not useful. and it will be up to the investigators once they do find the wreckage and try and figure out what happened. >> greg feith, stay with us.