Residue from a shell likely stayed burning inside the gun barrel and set off the next round during a tank gunnery drill at a Ground Self-Defense Force training ground in Oita Prefecture, an investigation has concluded. Four troops were killed or injured in the explosion.
The Ground Self-Defense Force finished compiling the findings, people familiar with the matter said on the 6th, according to Kyodo News. The investigation judged it highly likely that the leftover material caused the next shell to detonate.
The source does not give the date of the accident, the name of the training ground, the units involved or the ranks and ages of the four. It also does not say whether the findings have been made public or whether the force plans to change how it handles live ammunition.
The four were hit when a shell burst during firing practice. The investigation centered on what remained in the barrel after an earlier round, the point where a live-fire drill leaves the least margin for error.