The mass food poisoning incident at a free Thanksgiving dinner in Antioch that ended in the deaths of three people now has a clinical conclusion. As KRON 4 reports, Contra Costa County health officials have concluded that the culprit bacteria was Clostridium perfringens, one of the most common bacteria responsible for food-borne illness, though they can not say for certain which of the dishes served at the large group meal was to blame.

Investigators do know that of the 25 people sickened by what they ate that day, including the three who died, all seemed to have eaten turkey and mashed potatoes around the same time of the day, as the station notes. The bacteria was found in their stool samples. And the meal, organized by Golden Hills Community Church at Antioch’s American Legion Hall, served 835 people over several hours, with foods prepared by volunteers in private homes.

Clostridium perfringens is most commonly found in undercooked meat or cooked foods left to sit out too long, according to this site written by lawyers representing cases of severe food-borne illness. The bacteria is nicknamed “food service germ” because of its prevalence in meats, casseroles, and gravies that are allowed to sit at room temperature for too long before serving. Per Wikipedia, C. perfringens forms spores that are able to withstand cooking temperatures, which will then grow and proliferate if kept between 70 and 140 degrees for extended periods.

Incidents of death from C. perfringens have occurred in recent years in Canada and England after church potlucks or similarly served group meals.

Dr. Louise McNitt, a deputy health officer with Contra Costa Health Services, said in a statement, "Clostridium perfringens is one of the most common food-borne illnesses in the U.S. It can be found in the human intestine without hurting us, but eating food containing large amounts of this bacteria can cause illness and in some cases death."

Church leaders had apparently failed to obtain the proper permits to serve this big group meal, and county health officials says they're now working with them to "make sure they understand the permitting process."

The three deceased all lived in the same assisted living facility, and they were 43-year old Christopher Cappetti, 59-year-old Chooi Keng Cheah, and 69-year-old Jane Evans. All were brought to the event on Thanksgiving, and all three became violently ill afterwards.

Previously: Three Dead From Food-Borne Illness At Antioch Thanksgiving Meal Identified