A roll up guard curtain is disclosed having: a vertical frame structure having a base configured for a floor surface, first and second side supports each coupled to an opposing end of the base, perpendicular to the base, and extending upwardly, and an opening defined as a planar area within the frame structure between the first and second side supports and the base; a drum disposed within the base; a curtain disposed upon the drum and configured to extend upwardly from the drum by a curtain bar and retract downwardly to the drum; and a drive mechanism configured to extend rapidly the curtain upwardly from the floor surface and retract rapidly the curtain downwardly to the floor surface, to vertically raise and lower the curtain within the vertical frame structure, thereby to fill the opening when extended and to provide a rapidly extendable and retractable protective barrier.