Man, this is really sheety news. I knew David quite well from running in Europe.
I remember pacemaking with him in the Athens SGP in 2004 for the 1500 (I ran the first 900 and he ran through to 1200), and afterwards he comes up to me and says "hey man, I like you, you not like the other Kenyans - you tall", hahaha.
He was a genuinely nice guy that was very intelligent, very friendly and articulate. One of the nicest (and most talented) guys I met in eight years in Europe.
Just my little tribute to a great dude.