but their focus is on getting control of the aircraft aviating navigating and then communicating. so communicating is their last option. and one pilot told me today, the fact that they did not speak to air traffic control may indicate again, we say may indicate that they were still struggling to get control of the aircraft until the very end. >> a mystery. huge mystery. rene, thanks very much. rene marsh reporting. just ahead, we know when the germanwings plane started to descend descend. but that's raising a lot of questions about why it crashed. we have expert analysis coming up. janet? cough if you can hear me. don't even think about it. i took mucinex dm for my phlegmy cough. yeah...but what about mike? (cough!) it works on his cough too. mucinex dm relieves wet and dry coughs for 12 hours. let's end this.