On Tuesday evening, a semitruck full of liquid nitric acid rolled across an Arizona freeway, killing the driver and releasing toxic chemicals.
Arizona’s Department of Public Safety released a photo of the incident shortly after, cautioning citizens to use alternative routes while the freeway — Interstate 10 in Tuscon — was closed and setting up a half-mile perimeter.
The Tuscon Fire Department was on the scene to help, per Fox News.
It was originally expected to be cleared for Wednesday morning’s commute, but “while crews were attempting to remove the load from the commercial vehicle, gassing occurred,” according to the Department of Public Safety. At 4:55 a.m. a wider perimeter of a mile was issued.
An evacuation order was issued on Tuesday evening and lifted Wednesday morning. Those that are in the area have been given a shelter-in-place order and are warned by the department to turn off air conditioning or heaters, in addition to anything that brings in outside air.
Nitric acid is used to make ammonium nitrate used for fertilizers, plastics and dyes, per the Centers for Disease Control and Prevention. Low exposure can irritate the skin, eyes and mucous membranes, but higher dosages can cause bronchitis, dental erosion, delayed pulmonary edema and pneumonitis.