LUCKY SEVERSON: It was an exercise conducted for government officials in mid-June 2001, three months before September 11 -- a test to measure the country's level of "preparedness" to respond to a bioterrorism attack. A scenario that left unresolved some very troubling ethical issues. It was called "Dark Winter" and designed by a bioterrorism expert, retired Colonel Randall Larsen.

COLONEL RANDALL LARSEN (ANSER Institute for Homeland Security): We wanted to examine the fault lines between the federal and state and county and municipal responses. We wanted to see how they would operate if there were insufficient resources like smallpox vaccines.

SEVERSON: In this worst-case scenario, one part was real. There are not enough smallpox vaccinations -- only 15 million doses -- stored at the CDC in Atlanta, and almost 300 million would be needed to vaccinate everyone in the U.S. Smallpox can kill one out of three who get it and can spread like wildfire, as it did in "Dark Winter."

COLONEL LARSEN: One of the biggest debates early on in the exercise is who do you give the vaccine to?

SEVERSON: The participants in the exercise, from several branches of government, discovered many problems as the scenario unfolded. But none was more difficult, more gut-wrenching than who gets protected, who gets saved when there's only limited vaccine. Who lives, who dies?

COLONEL LARSEN: So do you vaccinate the military first, or is it schoolchildren? Is that the most important person to vaccinate? You want to protect the children, the future of the nation.

SEVERSON: Former Surgeon General C. Everett Koop says he thinks many elderly would be willing to forgo vaccinations to protect the younger generation.

DR. C. EVERETT KOOP (The Koop Institute, Dartmouth College): I have lived 85 good years, and if the time came that you had such a situation where there wasn't enough to go around, I suspect that the spirit of Americans would be such that if you had a town meeting, you said, "We can only treat 75 percent of you," you would have a sufficient amount of volunteers that would back out and say take the others first.

SEVERSON: The value of vaccinating children or the elderly was debated in the "Dark Winter" scenario, but the first order of business -- who was going to keep government running?

COLONEL LARSEN: Some of the folks in the room said, "Let's vaccinate 2.5 million people in the military active duty guard and the reserve." Some people said, "Wait a minute! I don't need M16s and F26s and M1 tanks." We need to vaccinate the public health workers, medical personnel, firefighters, police, people who will be responding. As the president, is your primary mission to defend America, or to defend Americans? It depends on how you answer that question of who is going to get it.

SEVERSON: William Galston teaches ethics and public policy at the University of Maryland. And he says the moral principle for public officials is to save lives, but not all lives have equal value.

PROFESSOR WILLIAM GALSTON (University of Maryland): What this means is that every human life is considered to be equally significant, but that doesn't mean that every individual is capable of making an equal contribution to the saving of human life.

SEVERSON: This is Burnsie's in Augusta, Maine --- a hangout hundreds of miles away from the terrorist attacks in New York and Washington, but like the rest of the country, a different place than before.

The customers now talk about scenarios once unthinkable -- who gets saved.

This is Jim Hunt, a lawyer from Portland.

JIM HUNT: They seem like awful questions to have to address at any time, but I think it'd be better that we start talking about these questions now rather than when you know the emergency is on us.

SEVERSON: Neil Gallagher, a systems consultant from Brunswick.

NEIL GALLAGHER: I would almost have to say you should do it by lottery.

SEVERSON: And Maine native Anne Robinson.

ANNE ROBINSON: Somebody once wrote that God might be able to be utilitarian, but we human beings cannot be, because we simply lack the capacity to make those kinds of judgments and discrimination.