KPTV reports that a Washington state petting zoo linked to four E. coli illnesses in children has voluntarily closed its petting zoo for the season.

The owner of Willow Grove Gardens in Longview, WA, told  Fox 12 last week the children may have become ill by petting the animals and not washing their hands, even though signs are clearly posted reminding visitors to clean up at a washing station by the petting zoo.

Handwashing is never enough.