The First National Bank Tower in downtown Omaha was evacuated just before 10:30 a.m. Friday due to a possibly hazardous material. Employees were given the "all clear" sign and started returning to work around 11:20 a.m.
Someone in the receiving department opened a box with a liquid leaking out. It turned out to be nitric acid, a common cleaning agent. Employees called 911 and the building at 16th and Dodge was evacuated over concern the acid would get into the ventilation system.
The substance was taken outside and the area inside properly ventilated. No injuries or illness were reported.