Condolences to the victims of a highly deranged person & may they have a speedy recovery. My salute to the three fellow NS trained citizens for their COURAGE in the face of an armed attacked, to SAVE MANY OTHERS LIVES...
During NS, many combat fit citizens would have to go thru strenuous Taekwondo training, everyone including even clerks, but sadly, some chose to 'keng' with excuses such as MC or supposed important work.
Taekwondo training, from white belt to black belt, it teaches one on how to defend oneself. TKD was developed centuries ago in response to oppression under Daimyo rule where citizens are NOT allowed to own arms, and suffered under brutality by armed samurais.
Those defensive & attack repetitive moves during training is to ensure that in an actual battle event, it would become INSTINCTIVE REACTION, as usually, there is no time to react but only upon training & instinct, a way of defensive life.
For example, one would have to assess the enemy intelligently. If he tall with long legs & arms, one would have to limit such advantage but getting close to him immediately, to not allow him to use long arms & legs to strike. If the enemy is short, with short arms & legs, then one can use one's longer arms & legs, to keep him a distance away, to deny him of any advantage, & many more other techniques......
Furthermore, there is also UNARMED COMBAT that is used to train NS soldiers. Bullets will eventually run out in desperate battles, & the only way to survive is to use unarmed combat moves to fight against enemies, especially at close quarters in trenches & rooms whereby long range rifles are not effective.
For example, an enemy will take at least 3 seconds to aim & fire. Any firing without aiming would mean a shot may not be able to take one down. It is this crucial 3 seconds that will save one's life - to rush forward, swing the enemy's rifle away & get him down.
Ultimately, the Art of War is about deceptions & distractions. Distract the enemy, eg - throw a chair or dustbin cover at him & while he is naturally focused upon the chair to defend himself, it will be time to close up the range between oneself & the enemy to bring him down.