The estimated 40 employees in the ConAgra plant on West Calumet in Centralia were evacuated late Monday night when the ammonia alarm sounded.
The Centralia Fire Department was called to shut off a valve in a small outside building where the ammonia tank is located. A small leak in a connection between two pipes was discovered to be the problem. After additional firemen and more management personnel arrived the leak was further isolated in the building.
Only a small level of ammonia was found in one area of the main plant, but employees were not allowed to return for the two-and-a-half hours firemen were on the scene.
An outside contractor was called to repair the problem.
Firemen received the call at 11:30 Monday night.
