The 1918 influenza virus killed 675,000 people in the United States, out of a population not much more than one-third the size of today's.

-- "The Great Influenza: The Epic Story of the Deadliest Plague in History," by John M. Barry

"I have thought through the scenarios of what an avian flu outbreak could mean. I tried to get a better handle on what the decision-making process would be by reading Mr. Barry's book on the influenza outbreak in 1918. I would recommend it."

-- President Bush at his news conference Tuesday

Some excerpts from Barry's book:

In ten days -- ten days! -- the epidemic had exploded from a few hundred civilian cases and one or two deaths a day to hundreds of thousands ill and hundreds of deaths each day.

Federal, municipal, and state courts closed. Giant placards everywhere warned the public to avoid crowds and use handkerchiefs when sneezing or coughing. Other placards read "Spitting equals death." People who spat on the street were arrested -- sixty in a single day. The newspapers reported the arrests -- even while continuing to minimize the epidemic. Physicians were themselves dying. . . . Health and city workers wore masks constantly.

What should I do? people wondered with dread. How long will it go on? Each day people discovered that friends and neighbors who had been perfectly healthy a week -- or a day -- earlier were dead. . . .

What was happening in Philadelphia was happening everywhere. In that densely populated city, Isaac Starr had counted not a single other car on the road in his twelve-mile drive from the city center home. And on the other side of the world, the same experiences -- the deaths, the terror, the reluctance to help, the silence -- were replicated. . . .

The federal government was giving no guidance that a reasoning person could credit. Few local governments did better. They left a vacuum. Fear filled it. . . .

In 1918 the lies of officials and of the press never allowed the terror to condense into the concrete. The public could trust nothing and so they knew nothing. So a terror seeped into the society that prevented one woman from caring for her sister, that prevented volunteers from bringing food to families too ill to feed themselves and who starved to death because of it, that prevented trained nurses from responding to the most urgent calls for their services. The fear, not the disease, threatened to break the society apart. . . .

So the final lesson, a simple one yet one most difficult to execute, is that those who occupy positions of authority must lessen the panic that can alienate all within a society. Society cannot function if it is every man for himself. By definition, civilization cannot survive that.

Those in authority must retain the public's trust. The way to do that is to distort nothing, to put the best face on nothing, to try to manipulate no one. Lincoln said that first, and best.

Leadership must make whatever horror exists concrete. Only then will people be able to break it apart.

In this 1918 photograph, people with influenza crowd into an emergency hospital at Kansas's Camp Funston.