Due to faulty planning of the protection of the underground defense tunnels beneath the main citadel, one direct artillery hit caused a huge explosion, which eventually led to the surrender of the Belgian forces.
Zbog loše isplaniranog podzemnog sustava obrane u tunelima ispod glavne tvrđave, jedan topovski pogodak je izazvao veliko eksploziju koja je na kraju natjerala belgijske snage na predaju.