Two Texas toddlers died after being left in a hot car intentionally for hours by their teenage mom who ignored their cries and then lied to investigators about what happened, authorities said.

Amanda Hawkins, 19, of Kerrville, is facing two counts of child endangerment in the deaths of daughters, Brynn Hawkins, 1, and Addyson Overgard-Eddy, 2, on Thursday.

“This is by far the most horrific case of child endangerment that I have seen in the 37 years that I have been in law enforcement,” Kerr County Sheriff Rusty Hierholzer said in a news release Friday announcing Hawkins’ arrest. He said a grand jury could upgrade the charges.

“Blonde, blue-eyed kids,” he told Fox 29 San Antonio in a report that aired Friday.

Hierholzer told the station Hawkins and a 16-year-old boy drove to a friend's house Tuesday night and left the children in the car while they were inside. Temperatures were in the 80s at the time.

He said the kids were alone in the car for 15 hours except for a brief time when the boy went out to the car and went to sleep before going back inside.

“We had heard that someone in the house could even hear crying and told her to bring them in the house and she didn’t,” he said.

She said, “No, they’re fine. They’ll cry themselves to sleep,” the sheriff said, KSAT-TV reported Saturday.

Hierholzer said Brynn and Addyson were unconscious by the time Hawkins drove them home around noon Wednesday. She bathed them and changed their clothes.

Eventually, others urged her to take the children to the hospital, Fox 29 reported.

At the hospital, she told doctors that the girls had collapsed while smelling flowers at a lake that may have been poisonous.

Investigators were notified and interviewed Hawkins.

“I think she pretty much admitted to what happened,” Hierholzer told Fox 29.

Brynn and Addyson were taken off ventilators Thursday afternoon.

Hierholzer said autopsies have been ordered.