First, both cities were unsuitable for firebombing targets, mainly due to the river deltas preventing the firestorms from being very effective. Second, both cities had terrains which provided a good measurement for damage caused by the nuclear bombs.[4] Third and finally, both cities contained strategic personnel and installations; Hiroshima was the headquarters of the 2nd General Army and 5th Division with 40,000 Japanese combatants stationed within the city's limit, and Nagasaki contained two large Mitsubishi armament factories and many other medium-to-small workshops and plants providing vital war components for Japan's war machine. In both cities, as with other Japanese cities, these targets were mixed in with civilian homes, schools, and temples. For example, at least 54% of the deaths in Hiroshima were combatants and slave laborers while 72% of the deaths in Nagasaki were war industry employees and slave