What caused plane to crash?

The discovery of debris from AirAsia Flight QZ8501 means investigators have taken a big step toward answering the questions haunting the families of those aboard the doomed plane. What are the key questions, and what might come next?



from CNN.com - Top Stories http://edition.cnn.com/2014/12/30/world/asia/air-asia-whats-next/index.html?eref=edition