A stretch of Interstate 10 in Tucson, AZ is closed in both directions after a truck carrying hazardous materials overturned, and people within a one-mile radius of the incident have been ordered to evacuate. As of press time, the Arizona Department of Transportation did not have an estimated time for re-opening.

There’s been no official word about what the substance is, though many observers have commented that due to the color of the smoke it could be nitric acid.

Prior to the accident, the National Weather Service issued visibility warnings for I-10 due to blowing dust.

Given the situation in Ohio, where a train carrying hazardous materials derailed February 3 resulting in massive fires that released deadly toxins into the air and water, Tucson residents are demanding quick information and response – as they should.

(This is a breaking story. Updates will be reported as they become available.)