(CNN) -- The body of a woman was found near her car Wednesday, the apparent victim of an ammonia leak from a nearby plant in Swansea, South Carolina, police said.
The leak occurred at the Tanner Industries plant as a hose had been connected from a delivery trailer containing anhydrous ammonia (purified ammonia) to a storage tank in the facility, said David Binder, director of quality safety and regulatory affairs for Tanner Industries.
"During that operation, a hole burst in the hose," he said. "That released ammonia gas."
The leak from the plant, located about 24 miles south of Columbia, was reported to the Lexington County Sheriff's Department shortly before 8 a.m., said Maj. John Allard, a public information officer for the department.
Firefighters arrived within 10 minutes at the plant, where they saw a large, light-colored, dense plume, and closed area roads to traffic, he said.
The ammonia hovered first over U.S. 321, then moved into a wooded area, blackening its foliage, Allard said.
Public safety personnel searched the vicinity for any people or animals affected by the leak, and -- at 9:30 a.m. -- found the woman's body next to her vehicle, which was parked on the side of U.S. 321, he said.
Officials were speculating that the woman had been driving north when she encountered the plume and tried to turn around, but her car stalled.
She apparently got out of the vehicle and was overcome by the fumes, Allard said. An autopsy has been ordered.
The woman's name was not released pending notification of her family.
Seven people were taken to Lexington County Medical Center in stable condition with respiratory problems, none of which was life-threatening, Allard said. Five were plant workers; the other two were nearby residents.
The road was reopened at 2 p.m., after the plume had dissipated, he said.
The U.S. Chemical Safety Board -- an independent agency charged with investigating industrial chemical accidents -- announced it is deploying an investigation team to the site of the ammonia release.
Tanner's Binder described the occurrence as "tragic," adding that nothing similar had occurred in the plant's more than 13 years of existence. "This is just heart-wrenching," he said, adding that there were no immediate plans to reopen the plant.
Ammonia, a strong irritant that affects the respiratory system, is used in a variety of industries, including the manufacture of fertilizers and in commercial refrigeration systems.
CNN's Anna Rhett Cobb contributed to this story
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