MOUNT PLEASANT, Texas – An ammonia leak at a Pilgrim's Pride processing plant sickened dozens of workers Aug. 24 and forced the evacuation of more than 700 workers from the plant. 

JBS, parent company of Pilgrim's Pride, said nine employees were transported by ambulance to the the Titus Regional Medical Center where they were under observation for an hour. No one was admitted to the hospital, according to the company. At lease one employee drove to the hospital for treatment.

JBS said the incident occurred while a contract worker was performing a maintenance procedure on the roof of the facility. The leak was stopped within 30 minutes. Workers were able to return to work the same day. Local news reports said the leak stemmed from a ruptured a line carrying anhydrous ammonia. JBS said the specific cause of the leak is still under investigation.