A California preschool teacher needed some added help when it came to nap time.

Debbie Gratz, 59, of Morgan Hill, Calif., was arrested Monday morning for crushing up sleeping pills and putting them in her students’ sippy cups, ABC 7 reports. She was caught Friday morning after an employee saw her putting something into the children’s cups, according to the news outlet.

Gratz admitted it was the sleeping aid Sominex and was fired,  KION reports.

“As a parent, you give this trust that you not only drop off your kids, which is difficult enough, but then that trust to be just crumpled is very disheartening,” Morgan Hill Police spokesman Sgt. Troy Hoefling told KCBS.

Gratz, who worked at Kiddie Academy, was in charge of 10 children between the ages of 1 and 2 years old, according to KION. At first, the school tried to handle the matter internally but later contacted the police.

"Sickening, sick to my stomach, I want to throw up," Bianca Flores, a parent of a 2-year-old who was in Gratz’s class until 2 weeks ago, said to ABC 7, describing her reaction to the news.

The school dumped the contaminated water down the drain, which could have been used for evidence, making the investigation a bit more complicated, according to the news outlet.

"What we would like to know is: Is there any tell-tale signs that they've seen now that they know, were their kids excessively tired or lethargic?" Morgan Hill Police Sergeant Troy Hoefling said.

Flores, whose son Caleb suffers from seizures, told ABC 7 she is taking him to the doctor to see if Sominex is a factor.

"I'm not angry; I'm just sad, disturbing. I don't know what to think," she said.