In her Pulitzer Prize-winning book, The Guns of August, Barbara Tuchman chronicled how a cascading series of seemingly minor developments led inexorably to World War I and the worst carnage known to man up to that time.

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As a result, campus officials didn't send out an email alert about the first two killings until about the time Mr. Cho was preparing to continue with his carnage.

WSJ: Virginia Tech Is Liable in Shootings

As the country surveys the carnage on Wall Street, the small-stock people think their time has come.

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