A tomato recall due to risk of salmonella contamination has been designated as Class I, the U.S. Food and Drug Administration's highest warning level, the agency said. The FDA marked the tomato recall affecting three states as Class I, meaning there is a risk of "serious adverse health consequences or death," on May 28.

The recall of tomatoes distributed in three southern states was upgraded to the most severe warning the agency issues.

FDA expands tomato recall across 14 states due to deadly salmonella contamination. Learn which brands and locations are affected by this urgent food safety