The Associated Press
2/6/2004, 12:48 a.m. CT

ANNISTON, Ala. (AP) -- Officials at the Army's chemical weapons incinerator spent Thursday trying to figure out why small amounts of a deadly nerve agent were detected in an observation room.

Operations at the Anniston Chemical Agent Disposal Facility shut down Wednesday afternoon after a monitor detected sarin gas in the air and on two workers. The Army resumed operations around noon Thursday, about 20 hours after the initial alarm.

No one was injured, but trace amounts of sarin escaped the plant's most protected area when the two workers were transported from the main furnace building to the incinerator's medical center.

Other workers put on protective masks and evacuated the corridor, located inside the building that houses the incinerator's three furnaces. No agent left the building, spokesman Mike Abrams said.

The incinerator was destroying rockets filled with gelled or crystallized sarin.

The alarm indicated a "minute" amount of chemical agent in the area, the Army said in a statement. Sarin is extremely dangerous; just a drop can kill.

"The workers didn't have enough agent to harm the community or them," said Tim Garrett, the Army's project manager at the incinerator.

Garrett confirmed that the alarm sounded at the medical center when the workers were brought in. He said both the furnace building and the medical center are under engineering controls, which means they have measures to curb the spread of contamination.

Officials said the two workers were changing filters that had become choked with crystalline agent and somehow got chemical agent on their protective clothing.

After leaving that area they moved to a decontamination room, where their suits were to be cleaned of any agent. From there, they went to another room, where the suits were removed.

The contamination probably came from some sort of backdraft or air blowing in the wrong direction, from a contaminated area to the observation room, said Bob Love, project manager for Westinghouse Anniston, the contractor operating the incinerator for the Army.

"It needs to be fixed," Love told the Birmingham News. "We'll have to change air flows or open doors slower or something."

Alarms have occasionally sounded at the site since it began destroying weapons six months ago, but Abrams said officials viewed the latest alarm as more serious because of its location.

"I am not aware of another situation that has put us on edge like this did," he said.

Some 35,000 people live within nine miles of the incinerator, located in east Alabama about 50 miles east of Birmingham. The incinerator is the Army's first to be located in a populated area.

About 2,254 tons of Cold War-era chemical weapons were stored at the depot for more than 40 years in earth-covered, concrete-reinforced bunkers. The incinerator has destroyed 17,991 rockets and 19,521 gallons of liquid GB since it began operations last year.