Assertion: bomb's effect | /r/HasProperty | observed
Facets:
Source sentences:
text: After being selected in April 1945, Hiroshima was spared conventional bombing to serve as a pristine target, where the effects of a nuclear bomb on an undamaged city could be observed.
text: The ElectroMagnetic Pulse (EMP) effect  was first observed during the early testing of high altitude airburst nuclear weapons