It finally happened. Well over 100 successful flights with nary an incident. I lifted off, did a check while hovering in front of me, 9 sats, all fine and then pushed forward. At about 20 feet it started acting odd and then started to drift and then accelerated at a 45 degree angle, narrowly missed ditching in the harbor and finally crashed into the rocks along the shoreline. 5 seonds from start to end - little time to react but the controls I did try appeared unresponsive. Either a motor shut down or it was the ubiquitous city-wide WiFi channel - they have two channels in tandem and for the heavy tourists influx. I noticed the town wifi signal on one corner of my property the ofther day .... this is all new in recent months and the signal strengths appear to be increasingly more powerful. Hard to walk through it as it was so fluid and happened so fast. But lets try ,,,,,