ABC News staffers have just gotten the all clear to return to the bureau after they had been evacuated, with sources confirming the move was triggered by the discovery of a "white powdery substance."
According to subsequent tests, says ABC, the powder was an aspirin-based substance."
ABC News President David Westin had sent out an e-mail at about 1 p.m.:
"Contractors doing some work in the basement of our Washington bureau came across some powder they found suspicious. Out of an abundance of caution we have evacuated the facility until the authorities can confirm that this is nothing to worry about. We will let you know when we have further word."
According to one source, the powder was discovered in a mail room, suggesting the anthrax scares that followed 9/11