HERMISTON, Ore. (AP) — The Hermiston Fire Department says a wildfire has scorched nearly 5 square miles and burned several buildings at the former Umatilla Chemical Depot.

Fire Capt. J.W. Roberts says the blaze that began Monday has scorched multiple bunkers, or igloos, where chemical weapons were once stored.

The East Oregonian says the fire has burned more than 3,000 acres and was about 30 percent contained as of Monday afternoon.

The depot no longer stores chemical weapons and the incineration plant used to destroy them has been torn down.

Roberts says the spark of the fire may have come from an Oregon Army National Guard member training with an "artillery simulation round" though the state military department considered the cause under investigation.

Multiple vehicle crashes were reported on Interstate 82, shutting down traffic for several hours Monday. Four people were taken to local hospitals.

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