This is not the happening for Tucson bros. It just fucks up traffic. So I used to work at a plant that used nitric acid in quantity. It was delivered by tanker trucks. One day a truck arrived which was leaking - they had loaded nitric acid into the wrong kind of trailer and it was dissolving the steel. The nice part was that we had an offload location that was in containment. We moved the truck there, whereupon the acid continued to eat the trailer and leak at an increasing pace. It was a hell of a mess, and there was a lot of fume for a while, but it was not a major health concern like Ohiogeddon. Nitric acid is nasty stuff - don't get me wrong - and driving through the smoke would be a terrible idea, but I think this will not be a big deal for the area judging by the picture. They'll clean up what they can out of the median, neutralize what they can, and that will basically be the end of it. The acid is water soluble - so if the remainder seeps in to groundwater over time it will diffuse over time too (not sure how much time, but an aquifer could dilute a lot of acid to less than harmful concentration). It's not like pouring it down your well. I think this will not be a big deal in the end. The aftermath of the leak in the plant was fucked up concrete and underground utilities all underneath a big rig that was devoured by acid. We saved the chemical company's bacon by containing the shipment - they helped fix the problems it caused, and nobody got injured. All good.