I'm the author of the ASHFALL three-and-a-half-ology: ASHFALL, ASHEN WINTER, SUNRISE, and DARLA'S STORY.
This book could serve as a case study for the perils of self-publishing--Wilkins is an amazing man, and his story is nothing short of awe-inspiring. He stayed behind and protected those he could during the Rwandan genocide, saving hundreds of lives. But he tells the story so poorly that few will ever discover this book.
At a prose level, it's not bad, although there are many sentences and paragraphs that could stand improvement. But the narrative arc of the story is buried in a poorly thought-out and frequently boring chronology of events. It's an impressive first draft that in no way was ready for publication. Far, far too many writers make this mistake: just because you can self-publish doesn't mean you should. A skilled editor could have turned Wilkins's story of his exceptional heroism and compassion into a truly remarkable book. Instead, at the end of the book I was left with the disquieting feeling that I should have felt inspired, and was vaguely guilty at feeling bored instead.