The Tennessee Department of Health is investigating a possible foodborne illness outbreak after 19 workers at a Walmart distribution center in Lebanon, Tennessee, were taken to hospitals, NewsChannel 5 Nashville, WSMV and Fox 17 Nashville reported.

The department said the possible outbreak is associated with a meal at the facility, Fox 17 reported. It is working with the Mid-Cumberland Regional Health Office, the Wilson County Health Department and Walmart officials, the station said.

Newly released 911 calls show the emergency began with one worker who was vomiting and tired in a restroom, NewsChannel 5 and WSMV reported. In a later call, a caller said the number of sick workers was growing. "So we're currently sitting at 28 affected associates, and we have at least four that are very ill," the caller said, NewsChannel 5 reported.

When a dispatcher asked what the patient might have eaten, the caller said, "It's possibly from homemade rice that was brought into the facility," NewsChannel 5 reported. WSMV also reported that a caller said a homemade rice dish may have been involved. Health officials have not confirmed that rice or any other food caused the illnesses, NewsChannel 5 said.

Responders first heard that 80 or more people might be affected, Wilson County Emergency Management Agency officials told NewsChannel 5. Crews triaged about 25 to 30 people and took 19 to hospitals, the outlets reported.

"Foodborne illness is caused by consuming contaminated food or beverages," health department spokesperson Bill Christian said, Fox 17 reported. Walmart has said its products were not the source and there is no risk to the public, NewsChannel 5 reported.

Dr. William Schaffner, an infectious disease professor at Vanderbilt University, told NewsChannel 5 that investigators will try to find the cause and look at how the food was prepared and handled. "The rule is heat it, cool it, never leave it out," he said.

What we know: Nineteen workers were hospitalized, and state health officials are investigating a possible outbreak tied to a meal.
What we don't: Which food, if any, caused the illnesses, and how the sick workers are doing.