Authorities in South Hutchinson say two contract workers were hurt when anhydrous ammonia leaked at a Tyson Food plant. This is the latest in a string of accidents at the plant involving ammonia. One of those accidents cost a plant worker his life.

South Hutch Police Chief Scott Jones says one of the workers was treated at the scene after the leak on Thursday morning. The other was taken to a hospital for treatment of undisclosed injuries.

The plant’s employees were evacuated until the leak was contained.

The plant produces pepperoni, precooked hamburger, sausage crumbles and meatballs, and uses anhydrous ammonia as a refrigerant.

Tyson Food has shelled out millions of dollars in fines for incidents involving releases of anhydrous ammonia. In 2013, the company paid a $3.95 million civil penalty to close investigations into eight incidents between 2006 and 2010. An October 2006 accident in South Hutchinson killed a plant worker.