The Canadian Food Inspection Agency (CFIA) first learned of the potential hazard to Canadian consumers in mid-August, 2012, when a sample of lettuce imported from California tested positive for E. coli O157:H7. The agency issued a "Health Hazard Alert" notice, warning the public not to consume the Tanimura & Antle lettuce on August 17, 2012. By August 20, both the CFIA and the U.S. food and Drug Administration had announced that Tanimura & Antle was recalling "Wrapped Single Head Romaine" due to potential E. coli contamination.
According to Canadian health authorities, the people who became ill with E. coli O157:H7 infections after eating the lettuce were from Ontario and Alberta. Marler Clark represents the family of the Alberta woman, who died following her E. coli infection, in a claim against Tanimura & Antle.