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 US dropped an atomic bomb on the city 73 years ago.