Equipment failure stalls Senate anthrax fumigation

WASHINGTON (CNN) -- The fumigation of the ventilation system at the Hart Senate Office Building to rid the structure of anthrax spores had to be aborted early Monday morning because of a mechanical problem, officials said.

An earlier report that the fumigation had been completed was wrong, said Ltd. Dan Nichols of the U.S. Capitol Police. He blamed miscommunication between different agencies for the inaccurate report.

Under the direction of the Environmental Protection Agency, chlorine dioxide gas was pumped through the ventilation system beginning at about 9 p.m. EST Sunday. But due to an unspecified mechanical error, the gas did not properly saturate the area, Nichols said.

Officials decided to abort the fumigation process before daylight Monday and have not determined when they might try it again, Nichols said

The Hart building has been closed since October 17, when aides in Senate Majority Leader Tom Ashley's office opened a letter filled with anthrax spores.

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The fumigation of the ventilation systems, which began late Sunday afternoon, had originally been scheduled to begin Friday night, but experts were unable to raise the humidity inside the building sufficiently until Sunday, said Richard Rupert, who is coordinating for the Environmental Protection Agency.

The Hart building is just one of several congressional office buildings that were contaminated with anthrax.

Anthrax cleanup at the Long worth House Office Building -- where four offices were contaminated -- also has been completed, but it will take about a week to renovate the offices to ensure they are habitable. In addition, a couple of offices in the Ford House Office Building remain closed.

-- CNN Senate Producer Dana Bash contributed to this report