MINNEAPOLIS (AP) _ Minnesota health officials are investigating the source of an E. coli strain that has taken the life of a 3-year-old girl and hospitalized her older brother.

The parents of Kallan Maresh say the bacteria toxin attacked their daughter's kidneys and neurological system and led to her death. Kallan and her 5-year-old brother, Kade, contracted the bacteria July 9, sending them into kidney failure.

State health officials say the children could have been infected from any number of sources, but as a precaution, animals at a petting zoo the children recently visited have been taken off display.

The family, from Wright County, said on the CaringBridge website, that after several visits to the emergency room, the siblings were taken to Children's Hospital.