Fail-Safe Detonation is a term that is used to explain the self-destruct system of a WIA or KIA SPARTAN-II's armor. Once a SPARTAN-II is killed or wounded fatally, the protocol will have to be enacted by either themselves or a nearby Spartan. This is done to avoid capture of the suit and/or the wearer for identification or technological study. It is unknown if the Mark VI has this capability, since the Mark V is said to have one.