If you have a close look at the footage around 0:40 and watch him accelerate up and off the ground then straight downwind at high speed, that can only come from a kite looping back toward the water.
Maybe a rider error, maybe a gear failure...bottom line is kiting in a tropical storm with clouds like that in the background and concrete buildings within a few 100m, it's going to be a bad time for anything to go wrong.
Makes you really wonder about the power of looping kites in high winds.....I'm going to be doubly careful next time I pull the trigger on the 8m in 25+

Anyway, lets have some compassion for the guy, his family and friends. We all make mistakes, he has made one now too, and has paid a very heavy price.
Could be one of us next time.................