Each plane crash is a tragedy, but speculation as to what happened in France are fruitless until the flight recorders are found and decoded.
Sincere condolences to the families...
They already found it, though not sure how long it takes to decode. Don't flight recorders only collect certain flight data? I guess if it was shot down or just blew up randomly the box wouldn't be able to help (not saying it was anything to do with those two but speaking in general about crashes).
Crew conversations are actually recorded by (at least some) flight recorders, so you should still be able to infer something about circumstances of accidents. As an example, in the
Aerolinee Itavia Flight 870 case pilots chatting about nearby aircrafts movements suddenly stop, due to the airliner being hit by a missile.
My knowledge is that there are usually two different "black boxes" in a single plane although they can sometimes be integrated into a single unit. One is the flight data recorder (FDR) which records the technical details of the flight (e.g. control inputs, airspeed, altitude, pitch, roll, yaw, magnetic heading, etc.) while the other is the cockpit voice recorder (CVR) which records the conversations in the cockpit.
The fact that they didn't maneuver at all is definitely weird. I believe visibility was decent so it's not like they didn't see mountains coming if they were alive and conscious.
Interestingly, one of the theories currently circulating as to the cause of the disaster is that the pilots of the plane lost consciousness due to a cracked windscreen and the resulting loss in cabin pressure which would have knocked them unconscious or otherwise incapacitated them to some degree:
According to reports circulating on professional pilots forums, the catastrophic crash could have been triggered by a sudden loss of cabin pressure...
...Rumours have been circulating that the cockpit's windscreen gave way, incapacitating the pilots and rendering them unable to send a distress call.
Link:
http://www.express.co.uk/news/world/566170/Alps-crash-Rumours-circulate-cracked-windscreen-blame-Germanwings-tragedy