The scenarios are grim: A pandemic influenza swamps the availability of hospital ventilators. A chemical spill exhausts antidote supplies and decontamination abilities. A terror attack overwhelms ambulances and trauma centers. A big earthquake, wildfire or hurricane throws emergency rooms into crisis. At the prodding of the federal government, state health departments nationwide are hurrying to complete "Crisis Standards of Care" plans to guide medical professionals in such catastrophes and determine what should trigger them. It's no easy task: Plan architects must navigate the ethical and legal minefields that would arise if there are more patients than providers at hospitals, clinics and other medical settings are set up to handle in usual fashion.