Before classes started this morning, a tank of liquid carbon dioxide began venting non hazardous carbon dioxide gas through a release valve on­Barstow Ave. between Chestnut and Willow avenues. ­The tank was being used in a soil experiment on the Fresno State Farm, on the east side of campus.

When the glass cloud was reported, University Police Officers and Fresno Police Emergency crews were dispatched and the road was closed as a precaution, said Mike Mosinski of the University’s Agricultural Operations.

Power was restored to a cooling unit, another valve was opened to channel gas into the soil and the venting stopped. Barstow Ave. has been reopened.