A new day care worker was so concerned by what she saw in June that she says she snapped a photo of a toddler who was strapped to his nap mat with duct tape.
That employee of Heart2Heart Montessori Academy in Willow Park, Texas, notified parents and authorities and then quit her position.
The child's parents, Kristi and Brad Galbraith, said they confronted day care co-owner Pamela Decker.
"Once I told her we had photographs, she broke down at that point and started apologizing and admitted to what she'd done," said Brad Gilbraith. The couple filed suit against Heart2Heart Montessori on Tuesday.
According to the Galbraiths' lawsuit, the day care whistle-blower said Decker told her, "Do not say anything about this. I know it's illegal, but (I) felt it was necessary."
The Galbraiths started talking to other parents. Lori Almquist said her child was taped to a mat the same day, and that the day care co-owner called to apologize.
Parents began sharing other concerns about kids being unusually thirsty.
"Kristi and Brad found out this day care center purposefully withheld water from children in an attempt to limit the number of times diapers had to be changed throughout the day," said Jeff Rasansky, the Galbraiths' attorney.
The couple said they sued because authorities have failed to act, and that they haven't even been contacted by Child Protective Services (CPS).
CPS tells WFAA-TV that the investigation should be concluded within days. The Parker County district attorney's office said there is also an ongoing probe.
The Galbraiths said their son is too young to talk much, but that he did tell them he was hit while at the day care.
"He would tell us that when he would go to take a nap, 'Please don't hit me. Please don't hurt me.' Which is incredible to hear from your son," Brad Galbraith said.
Heart2Heart offered no comment on the lawsuit. The school remains open, although Pamela Decker is no longer permitted on the property.
CPS previously reported that an inspection just prior to the tape incident found zero deficiencies.