Federal authorities are questioning working conditions at a Georgia auto parts plant for the eighth time in four years.
The Occupational Safety and Health Administration launched an inquiry of Sewon American in LaGrange after complaints of excessive heat and the death of an employee.
Teresa Pickard died May 29 after saying she was having breathing troubles at work. The state medical examiner has not released a cause of death.
The firm, which makes chassis and other parts for Kia and Hyundai, has said in a statement that Pickard's death was not work related.
Former employees told The Atlanta Journal-Constitution about sweltering conditions, inadequate air conditioning and poor access to water.
Sewon has faced fines in the past for ignoring safety problems that threaten workers.