Cantaloupe grown on Jensen Farms was the source of a Listeria outbreak that killed 33 people and sickened another 147 people in 2011. The owners of the now bankrupt company, brothers Eric and Ryan Jenson, face criminal charges stemming from the outbreak and could potentially face six years in prison.

According to USA Today, the two men appeared in U.S. District Court in Denver on Thursday afternoon. They are each charged with six misdemeanor counts of introducing adulterated food into interstate commerce. They were released on $100,000 bond and face up to six years in prison if they are convicted on all counts. They could also face up to $1.5 million in fines.

It’s rare for farmers to face criminal charges for an outbreak like this one, but it seems that federal prosecutors want to send a message. The U.S. Food and Drug Administration (FDA) linked the contaminated cantaloupes to Jensen Farms’ packing house, which had dirty water on the floor and old equipment. People in 28 states ate the cantaloupe, so the magnitude of the outbreak may have contributed to the decision to charge the brothers.

"The real significance of the case against the Jensens is they are being charged with misdemeanors, which do not require intent, just the fact that they shipped contaminated food using interstate commerce," said attorney Bill Marler, who urged the U.S. Attorney’s office to press criminal charges.

Listeria infections are caused by Listeria bacteria, which are most often found in food that is not properly washed or stored. Unlike most other bacteria, Listeria can survive refrigeration and freezing. Symptoms of Listeria infections include fever, muscle aches, nausea, and diarrhea. If the infection spreads to your nervous system, more severe symptoms like stiff neck, confusion, loss of balance, and convulsions can occur.

The epidemic linked to Jensen Farms was the deadliest outbreak of foodborne illness since the winter of 1924-1925, with 33 people losing their lives.