Early Sunday, a worker at a Tyson Foods plant in Tennessee found a toxic ammonia gas leak.
The leak was discovered overnight at the beef processing facility and triggered an evacuation of residents, including 280 people at an RV park in Goodlettsville, Tennessee.
In addition, 20 workers evacuated while plant managers and a hazmat team assessed the situation, according to the AP.
Emergency personnel were called around 4:45 a.m. and stopped the leak in less than four hours.
No one was hospitalized.
Ammonia is a part of the company's refrigeration system.
Officials gave the "all clear" after analyzing the perimeter with an ammonia-specific air monitor and detected no gas within a one-hour time frame.