UPDATE: From the NYT blog...
5:17 p.m. | Cause of Death Undetermined: Mr. Russert’s doctor tells NBC that Mr. Russert collapsed in the bureau, resuscitation was done immediately, he was transferred to Sibley Memorial Hospital where resuscitation was continued. The cause of death has yet to be determined and an autopsy being performed. This is at variance with what was on the NBC Web site, which said Mr. Russert had a heart attack.
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