Toddlers in 'horrific' death after mother intentionally leaves them in her car for 15 hours

'It was determined that the two young girls had actually been left in their mother's vehicle intentionally for over 15 hours,' county sheriff claims

Temperatures had reached 'into the 90s' during that day (stock image) (Getty Images)

Two toddler sisters died in a car after their mum intentionally left them in a car for more than 15 hours, authorities can reveal.

Amanda Hawkins has been named as the mother by Kerr County Sheriff W R Hierholzer in the US state of Texas.

In a news release on the tragic incident, he wrote: “Both girls passed away around 5pm on June 8, 2017. 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.”

Nineteen-year-old Miss Hawkins and her 16-year-old male friend were charged with two counts of abandoning or endangering a child, but the charges against her may be upgraded if the case goes to a grand jury, he told KABB.

Although the cause of death has not yet been confirmed, he did say that temperatures had reached "into the 90s" during that day.

Ms Hawkins took the children to the hospital, where she told staff herself and her friend had been at Flat Rock Lake, and the girls were smelling flowers. According to her initial account the one-year-old child collapsed first, and then the two-year-old swiftly followed.

However, after an investigation was opened and the duo extensively question, it was determined: “The two young girls had actually been left in their mother’s vehicle intentionally for over 15 hours, overnight… while she and other friends were inside a residence.

"They were in the house all night. The male friend for a little bit went to sleep in the car a little while but then went back to the house,” he added.

After discovering the girls, the mother reportedly attempted to give them a bath, and did not immediately take them to hospital for fear of reprisal.

Autopsies were scheduled to take place on Friday.