Details can be found here.
No-one who writes haiku in English could be unaware of Bill Higginson. He has probably done more than anyone else, up to and including RH Blyth, to bring haiku to the western world. His books are friendly and engaging, but also very intelligent and brimming over with passion.
His “Haiku Handbook: How to Write, Share, and Teach Haiku” was my reintroduction to haiku. It did a lot to shape my understanding of the form, and of where the form as written now, in English, was headed. It was actually the first book I ever bought online. (And if you don’t have a copy, get one now!) 
Then there were the two sajiki: Haiku World: An International Poetry Almanac and The Haiku Seasons: Poetry of the Natural World. They opened my eyes to the way that seasonal references could work in my world, rather than just some semi-mythological Japanese reverie. I still consult them regularly, although I don’t obey the rules of seasonality.
I never met him face to face, but I was in a few online mailing lists that he participated in. He was unfailingly kind and helpful, even to people who insisted that haiku must be seventeen syllables, and who obviously had no idea of either what they were talking about, or who it was that they were lecturing so rudely.
There are no words but the obvious. He will be missed.
