bombing of Nagaoka
... that during the bombing of Nagaoka in World War II, 80% of the urban area of the city burned down?
... that during the <b id="mwAaY"><a href="./Bombing_of_Nagaoka" id="mwAac" rel="mw:WikiLink" title="Bombing of Nagaoka">bombing of Nagaoka</a></b> in World War II, 80% of the urban area of the city burned down?