Those who revere John Hersey's Hiroshima as a classic piece of reporting about an act unprecedented in human history -- the instantaneous annihilation of tens of thousands of civilians by human agency -- may approach a new book on the subject with lowered expectations. But in Shockwave: Countdown to Hiroshima (HarperCollins, $26.95), Stephen Walker has painted on a larger canvas, beginning this tale of both ghastly destruction and a gamble to end a protracted war by visiting the site in the New Mexico desert where the atomic bomb was first tested. From then on, he switches back and forth from the United States to the doomed Japanese city, from the Imperial Palace in Tokyo to the so-called "Little White House" near Potsdam, Germany, where President Harry Truman got a briefing on the new weapon's progress in late July 1945.

In Hiroshima, Walker zeroes in on the experience of a soldier named Toshiaki Tanaka. Separated from his wife and child by his military duties when the bomb fell, Tanaka went searching for them the next day but knew there was no hope once he found a neighbor, recognizable only by a telltale belt buckle he had worn. Then Tanaka saw "two figures, like charcoal sticks, fused together on the ground, facing what was once the doorway [to the family-owned liquor store]. One of the figures was much smaller than the other, a tiny, shapeless bundle pressed against the other's back, as if somehow clinging to it. He knew immediately this was his wife and baby daughter.

"He stood perfectly still, staring at them. Despite the terrible burns their bones stood out. They were extraordinarily white. He could not understand how it was possible they were so white. He bent down beside them. Then he picked up the bones, placing them one by one in his handkerchief. . . . He walked out into the street that no longer existed and took the bones of his wife and child all the way back to the barracks in Ujina. There he placed them, still in their handkerchief, on a shelf above his bed in his quarters. It was the only home he had left."

-- Dennis Drabelle