malaysia flight 370. and the moment the mystery begins. >> you have a series of events that appear to be human driven. you have a transponder being turned off. you have an acars system being turned off. you have the plane being turned not once but at least twice probably three times. >> and most perplexing, no distress call. >> there are so many ways to notify people that there's a distress. uhf, vhf radio, many, many, many ways. >> none of that happened. >> none of that for seven hours. >> could it have been deliberate? to answer that question investigators zero in on the