A Cocke County, Tennessee child has died after fighting an E. coli infection. The girl, who was 20-months-old and was diagnosed with E. coli on October 9, was determined to be brain-dead on Monday and her heart stopped functioning late Tuesday night.

Officials with the East Tennessee Regional Health Department said Wednesday the source of Jaycee’s infection has not been confirmed, according to WATE.com.

The toddler’s family says Jaycee had a little bit of hamburger meat the Saturday before she got sick, but they don’t know if that was the cause of her infection.