Planet In Rebellion, George Vandeman.
"It was May 21, 1946. The place - Los Alamos. A young and daring scientist was carrying out a necessary experiment in preparation for the atomic test to be conducted in the waters of the South Pacific atoll at Bikini. "He had successfully performed such an experiment many times before. In his effort to determine the amount of U-235 necessary for a chain reaction&md;scientists call it the critical mass&md;he would push two hemispheres of uranium together. Then, just as the mass became critical, he would push them apart with his screwdriver, thus instantly stopping the chain reaction. But that day, just as the material became critical, the screwdriver slipped! The hemispheres of uranium came too close together. Instantly the room was filled with a dazzling bluish haze. Young Louis Slotin, instead of ducking and thereby possibly saving himself, tore the two hemispheres apart with his hands and thus interrupted the chain reaction. By this instant, self-forgetful daring, he saved the lives of the seven other persons in the room. . . (A)s he waited. . for the car that was to take him to the hospital, he said quietly to his companion, &ls;You'll come through all right. But I haven't the faintest chance myself' It was only too true. Nine days later he died in agony. Nineteen centuries ago the Son of the living God walked directly into sin's most concentrated radiation, allowed Himself to be touched by its curse, and let it take His life . . . But by that act He broke the chain reaction. He broke the power of sin.