It was supposed to be unforgettable, but for some who attended the Richey, Montana, Centennial last month, it was unforgettable for the wrong reasons.

Around 40 people from 10 states reported they had been infected with E. coli O157.

At least seven were hospitalized, and six Montana counties have been affected.

“If you had to have a foodborne outbreak, the timing couldn’t have been better,” says Jennifer Fladager, Dawson Co. Emergency Preparedness Coordinator.

Fladager had relatives who attended the celebration. She says staff members were prepared for this outbreak.

“We were aquatically trained and prepared for something like this. It’s rather ironic, we were just at a public health summer institute and we went over how to properly conduct case interviews with foodborne illness,” says Fladager.

Investigators say they have nearly completed their investigation and are working with the caterer to determine how the meal became contaminated.