FUKUYAMA, Japan (AP) — It's a sunny summer morning in the city of Hiroshima, Japan. Cicadas chirp in the trees. A lone plane flies high overhead. Then a flash of light, followed by a loud blast. Buildings are flattened and smoke rises from crackling fires under a darkened sky.

Over two years, a group of Japanese high school students has been painstakingly producing a five-minute virtual reality experience that recreates the sights and sounds of Hiroshima before, during and after the U.S. dropped an atomic bomb on the city 73 years ago Monday.

By transporting users back in time to the moment wh...