ROCHESTER, Minn. – A semi-truck carrying hazardous material crashed off an Interstate 90 exit ramp into Rochester and ended up on its side in a grassy borrow pit and smoking. First-responders sealed the site and re-routed traffic. The driver of the rig climbed out of the wreck on his own, apparently not hurt seriously. The cargo was canisters with legally required placards marked hazardous. Some canisters were leaking. It wasn’t immediately clear whether light smoke from the wreckage was related to the leaks. Early reports said the canisters held sodium chloride, known commonly as table salt, and hydrogen peroxide, used commonly in olden days to cleanse skin wounds. Neither is flammable or hazardous by itself. Whether the salt and peroxide  were in solid form or pressurized in a gas or liquid form was not immediately known. The first emergency crews on the scene called for the Rochester Fire Department’s chemical assessment ream. Also notified were the county emergency management director and the state Pollution Control Agency. A 300-foot safety perimeter was set up both directions on the right-of-way. A local alert to GPS-equipped vehicles and cellphones told motorists to keep a distance and upwind. The accident was about 7 p.m. on I-90’s Exit 218 onto northbound U.S. Highway 52 – one of two heavily traveled route into Rochester’s South End and about five miles out. Clean-up crews expected the ramp to be re-opened by midnight. The southbound ramps onto I-90 and the U.S. 52 route southbound to Chatfield were affected only briefly.

What we don’t know

> What caused he accident? Was other traffic in immediate jeopardy?

> Which canisters on board were hazardous? And how hazardous?

> Although the driver escaped serious injury, was he hurt at all?

> How familiar was the driver with the interchange?

> Where did the truck and its cargo originate?

> Where was the truck and its cargo headed?

> Was any ongoing highway construction and repair a factor?

> Was yhe narrowing of the ramp’s lane and a tight meld into Highway 52 a factor? The interchange has a record of frequent accidents.

> What was the source of light smoke from the wreckage?