seconds of what had been an uneventful flight. the plane was flying over rooftops as it it approached the birmingham airport over dawn. people awoke to what sounded like a flight in trouble. >> it was extremely low. then it sounded like it was sputtering, like it was out of fuel. >> reporter: seconds later, fire and explosions. >> i heard three booms. >> reporter: federal crash investigators are only beginning to find answers. a mystery compounded by an absence of critical communication. david mattingly, cnn, atlanta. >> you can't count on good luck to get you through a bad flight. that's why these investigations are so important. we'll stay on it. >> scary regardless. especially when you see how close it was to some of these homes. coming up next, a stunning announcement impacting 425 million gmail users. google admitting you should have no reasonable expectation of privacy. does that mean the internet