As one of few pilots in my circle of friends, I’m often asked, “what do you think happened?” I learned a long time ago to respond, “I really don’t know.” For one thing, my half century plus of experience is all in small airplanes, so I have no clue what happens in airliners, and for another and more important thing, I wasn’t there. I’ve lost friends in aviation tragedies, and I lost my own father in one. I wish I knew what happened in each case, but the best answer is still, “I really don’t know.”