A nuclear attack on a large U.S. city by terrorists--even with a low-yield improvised nuclear device (IND) of 10 kilotons or less--would cause a large number of deaths and severe injuries. The large number of injured from the detonation and radioactive fallout that would follow would be overwhelming for local emergency response and health care systems to rescue and treat, even assuming that these systems and their personnel were not themselves incapacitated by the event. The United States has been struggling for some time to address and plan for the threat of nuclear terrorism and other weapons of mass destruction that terrorists might obtain and use.