The news report here in California stated the copter "just fell from the sky". Looking at the wreckage I believe I see two engines. How does a helicopter, especially one with dual engines, just suddenly stop running and fall from the sky with no time to make a radio report of trouble? Copters autogyro when they lose power, they don’t just fall.
Something killed the electronic devices on that copter in mid-flight. . . Deliberately. I think a directed EMP. Our military has such a device. That would stop the engine, radios, cell phones, everything electronic on board. Including the electronic controls. ZOT!