Hermiston, OR -

The massive building where the Umatilla Chemical Depot's chemical weapons stockpile was destroyed has itself been destroyed.

The East Oregonian reports two pollution abatement stacks that were the final remnants of the Munitions Demilitarization Building were pulled down last week.

The chemical disposal facility incinerated about 3,720 tons of nerve agent from 2004 to 2011.

Closing the facility is expected to last through next year. The workforce is down from more than 800 workers to 149. Another 60 employees will be released in February after demolition ends.

The next steps are excavating several feet to make sure the site is clean and removing pipes and other equipment.