the plane. its last known altitude 6,000 feet. then flight 9525 disappeared from radar. >> translator: a terrible very sad day for germanwings and the whole louvre thauz saturdayust thauz thaunz saturday family. >> reporter: a government official said the plane was, quote obliterated. human remains strewn meters. french authorities say the pilot did not send a distress call or signal that there was trouble. it was air traffic control that declared an emergency because they couldn't reach the pilots by radio. leaving many unanswered questions. >> normally, even if you're on an oxygen mask in a depressurized plane or plane filled with smoke, you still will transmit on the radio, you still will set your transponder to the emergency code that air traffic control would pick up.