<human>:  How did the Air France Flight 447 crash?
<bot>: Air France 447 crashed into the Atlantic Ocean. It was a terrible tragedy, and it happened because of a number of factors. First, the pilots made a mistake by flying too low. They should have flown higher, which would have given them more time to react to a sudden change in weather conditions. Second, the plane was overweight, so it was flying too fast. Third, the plane hit a pocket of severe turbulence.