some of those answers are starting to come from the plane's cockpit voice recorder. this is the strongest clue investigators have in their hands. the exterior of germanwings flight 9525's cockpit voice recorder looks damaged but french authorities revealed today they have had some success. >> we are very glad that the first flight recorder has been retrieved yesterday and the french authority confirmed just a few hours ago that one of the audio streams is readable. >> reporter: the cockpit voice recorder captured audio up to the moment of impact. it will provide critical information like whether the pilots were talking in the minutes leading up to the crash. what were they saying and what else was happening in the cockpit. >> they're prepared to work with whatever they've got to get the information. it's more than just voice. they can hear what switches are being thrown and what buttons are being pushed. they can tell a lot about what's going on in the cockpit from