Sorry to hear this news, via Alex:
https://twitter.com/KendAlex/status/1183314157002731520
I don't know the details, and nor will I speculate.
I didn't know Dave very well, having only met him a couple of times in Japan. He seemed like a very nice guy, and certainly had a fantastic enthusiasm for kendama. Best wishes to his nearest & dearest.
Take care, folks.
Wow, shocking news indeed. Didn't knew him but his dedication to kendama was incredible.