If by "kill switch" you mean to interrupt a 16 kV circuit with current flowing through the switch, there are people and companies who know how to safely do this, and switches are made for just this purpose. If you need to ask the question here, you are unqualified to work on this type of equipment. The problem is air ionization creating a sustained arc as the switch is opened. This arc can extend for many inches because a low-impedance ionized air path is already present as the switch contacts open. The arc is extinguished by special switch designs, usually employing a strong permanent magnet to deflect and "blow out" the arc as the switch opens. And, yes, knife-blade switch designs are quite common for this application, as are vacuum relays.