Senate Building Cleared After Powder Found

Hazardous material crews work at the Russell Senate Office Building after it was evacuated on Capitol Hill in Washington, Wednesday, Feb. 8, 2006. The building was evacuated Wednesday night on a hazardous substance alert after police discovered a suspicious powder in its attic, authorities said. (AP Photo/Gerald Herbert)

This is off Yahoo News:

WASHINGTON - A Capitol office building was evacuated Wednesday night on a hazardous substance alert after police discovered a suspicious powder in its attic, authorities said.

The Homeland Security Department was investigating, but a senior counterterror official said it did not immediately appear to be an emergency.

Hazardous material teams and firefighters were dispatched to the Senate Russell Office Building after a sensor tested positive for a dangerous substance, the counterterror official said. A second test proved negative, and officials were conducting a third test in the evening for more conclusive results.

However, the official said the tests were a precautionary measure.

It was unclear what potential substances were detected, but the official said there was no indication of a nerve agent. The official spoke on condition of anonymity because of the investigation was continuing.

U.S. Senate staffers are seen quarantined inside a parking garage in the U.S. Capitol Complex after being quarantined there after a security sensor indicated the presence of a nerve agent at the Russell Senate Office Building on Capitol Hill in Washington, Wednesday, Feb. 8, 2006. Lawmakers, aides and other personnel were evacuated to the nearby West Legislative Garage as police conducted several tests before concluding that it was a false alarm. (AP Photo/Gerald Herbert)

I'm guessing that the suspicious powder was really dust-bunnies.