"Artifact" for a history project?

I have to create a museum display for dropping of the atomic bombs on Japan for a history project. I have all the written work down, but I need to create an "artifact" for it. This artifact is mainly to catch attention to my project and make it resemble an actual museum display. Some examples given were: an object, 3-D diorama, letter(s), or costumes. The artifact must be home made and not bought. Does anyone have an idea for an "artifact" that's closely related to the Dropping of the atomic bomb on Hiroshima and Nagasaki? I'd prefer not to make a diorama because of the short deadline given, and hopefully your ideas are easy to make. Thank you in advance.