That's impossible: each motor is independent of each other (with each having thier own ESC), meaning if one failed the others would still spin. With you it was different; there was a complete power failure every where, including the main computer which explains the sudden and abrupt end to the logs. Why, I don't know. At least they will provide a replacement.By the way, Cyberblitz was correct, 3DR came too the same conclusion, it was one motor that failed so all motors stopped. It seems that all the motors are connected so if one dies they all die. I have been told they will be replacing it with a factory refurbished unit, so that means I will be flying someone else's problem.