danger explosion explosive explosives pictogramm sign warning articles assassination attempt banned bomb bombing dangerous forbidden gas grenades material materials prohibited roadsign roadsigns signs tnt background backgrounds blue explosions light lights ray rays white canada dynamite Headframe Giant Mine NWT old panorama Yellowknife amunition army artillery attack bombshel bullet heavy military misfire missile rust rusty war weapon aircraft cannon barb wire black colors fast fire frequency gold green heat play of lights spark sparks speed wave yellow hot lava