The crew was under orders to only bomb visually. When they got to Kokura they found the haze and smoke obscuring the city as well as the large ammunition arsenal that was the reason for targeting the city. They made three unsuccessful passes, and eventually headed for Nagasaki and its torpedo factory, the alternative target. In Japan, the phrase "Kokura luck" was coined to describe lucky avoidance of the great misfortune without being aware of it.