HomeUPSCThe first detonation of an atom bomb took place in the summer of 1945 at: 169. The first detonation of an atom bomb took place in the summer of 1945 at:By Admin / October 4, 2025 A. Hiroshima. B. Nagasaki. C. Los Alamos. D. the Bikini Atoll. ✅ The correct answer is option C.