The review by N.K. Singh includes a haiku by Yasuhiko Shigemoto that seems dark and curious to me:

Mountains laugh.
Never say Hiroshima’s mountains
are laughing.

Yasuhiko has a self-introduction on his site that gives some background to this perspective:

When the Atomic Bomb was dropped on Hiroshima on August 6 in 1945, I was working at a factory about 2500 meters north of the A-bomb blast center as a student mobilizer. I was fifteen years old. Fortunately I did not have a burn, for I was in the shadow of a structure by chance.

An interview in the Belfast Telegraph fills in more details:

recalling the day he first saw the incinerated city of Hiroshima as a 15-year-old boy. “I walked across this bridge and even five days after the bomb, it was covered in charred bodies. I had to step over them, but there were so many I walked on someone. The river underneath was full of people too, floating like dead fish. There are no words to describe what I felt.”

No words but haiku. I couldn’t help but notice that he credits his interest in haiku to a chance meeting with an English school teacher imprisoned by the Japanese:

I met with HAIKU written by R. H. Blyth during the days of my Hiroshima University. I was surprised to know that he was absorbed in translating haiku into English at a concentration camp during the war. And at the same time, I felt much interested in his English translation of haiku and thought that I would like to write haiku in English or translate haiku into English as he he did. But for me, this was like a dream in those days. 　About thirty years later since then, I remembered what I thought about R. H. Blyth and haiku in my young days and began to try to tackle the work like a dream.