On July 15, 2009, about 8:00 a.m., a cargo transfer hose ruptured shortly after transfer of anhydrous ammonia began from a Werner Transportation Services, Inc. cargo tank truck to a storage tank at the Tanner Industries, Inc. facility in Swansea, South Carolina. A white cloud of anhydrous ammonia, a toxic-by-inhalation gas, moved from the parking lot of the facility across U.S. Highway 321 to a largely wooded area, where it eventually dissipated. About the same time, a motorist traveling north on the highway drove into the ammonia cloud, apparently tried to get away from the cloud, then got out of her car and died of ammonia poisoning. Seven people went to the Lexington Medical Center emergency department complaining of respiratory problems and dizziness; all seven patients were treated and released the same day. The anhydrous ammonia cloud caused temporary discoloration of vegetation in the area, including the leaves on the trees. Residents in the area sheltered in place, and U.S. Highway 321 was closed until about 2:00 p.m. on the day of the accident. The National Transportation Safety Board determined that the probable cause of the accident and made safety recommendations to the Federal Motor Carrier Safety Administration and the Pipeline and Hazardous Materials Safety Administration.