Amanda Hawkins, 19, is charged with two counts of child abandonment and two counts of child endangerment after leaving her two toddlers in a hot car in Texas for 15 hours. The 1-year-old and 2-year-old died after being brought to a hospital. (Photo: Courtesy of the Bexar County Sheriff's Office)

Police in Texas say a young mother "intentionally" left her two toddler daughters in a car for 15 hours, reports CBS affiliate KENS. The girls later died.

Kerr County Sheriff Rusty Hierholzer says 19-year-old Amanda Hawkins was in a Kerrville home with friends while her two daughters, 1-year-old Brynn Hawkins and 2-year-old Addyson Overgard-Eddy, were outside in the car from Tuesday evening until around noon Wednesday.

Hierholzer told CBS affiliate KENS some witnesses told police they could hear the children crying outside and told Hawkins to bring them in, but "she didn't want to."

"She intentionally left those kids in that car," Hierholzer said.

The sheriff's office says that the investigation began after Hawkins and her 16-year-old male friend showed up at Peterson Regional Medical Center with her two children, who were in grave condition.

Hawkins told hospital personnel that she, the girls and the 16-year-old had been at Flat Rock Lake. She said they had been "smelling flowers" in that area, and that the girls "collapsed" as they were getting ready to leave.

Read more.