An urgent care physician contacted the state health department to report a possible case of scombroid poisoning in May. The case stated he had eaten mahi mahi tuna for lunch at his workplace cafeteria in Minnetonka. Further investigation led to the identification of one additional case. The health department investigated the cafeteria and educated the workers on proper food temperature control. Health department workers also collected a sample of frozen tuna left over from the lunch and submitted it to the Food and Drug Administration (FDA) for testing. The FDA also began a traceback on the fish. The fish was a "product of Singapore" and had been shipped from there to California and Illinois prior to Minnesota. No violations in temperature or handling were noted during the transit in the U.S. or at the restaurant. FDA tests on the fish samples from the cafeteria had slightly high levels of histamine, but samples obtained from the distributor contained histamine levels over eight times the FDA standard. The likely cause of these elevated levels was temperature mistreatment of the fish early on in the supply chain.