Oregon Public Broadcasting

Security at the Umatilla Chemical Depot is high. That's because a driver rammed a 14-foot-wide farm tractor through the depotís perimeter fence and then fled Sunday night.

Military and non-military officials are still investigating the incident.

Bruce Henrickson is a Umatilla Chemical Depot spokesman. He says the tractor driver hasnít been found and the motives are not known.

Bruce Henrickson: "They didn't come near the chemical weapons at all and there was minimal damage, no one was hurt on post."

Henrickson says FBI officials responded to the scene. They've decided not to investigate further.

The depot still has large containers of mustard blister agent to process. But the other dangerous weapons like bombs and rockets have been destroyed.