Mom left 1-year-old son in hot car outside hospital where she worked for nearly 9 hours before he was found dead as temps reached 117: Police

Background: Northside Hospital Gwinnett in Lawrenceville, Ga. (WAGA/YouTube). Inset: Deja Coleman (Gwinnett County Detention Center).

An employee at a Georgia hospital allegedly left her 1-year-old son inside a hot vehicle for more than eight hours until authorities removed the child and, about an hour later, recorded the temperature inside at 117 degrees.

Deja Coleman, 29, has been charged with second-degree murder and second-degree cruelty to children, the Lawrenceville Police Department announced in a press release on Thursday. She was booked into the Gwinnett County Detention Center.

On Wednesday at about 6:55 a.m., Coleman arrived at Northside Hospital Gwinnett in Lawrenceville, Georgia. The city is some 30 miles east of Atlanta.

She had just dropped off her two older children at daycare as part of "her normal routine," after which she would "come back and retrieve the baby out of the car seat," Lawrenceville Police Captain Dena Pauly said at a press conference on Thursday streamed by area Fox affiliate WAGA. "Unfortunately, yesterday morning, she forgot to make that second trip to the car."

After the daycare trip, Coleman parked her vehicle in the parking lot of the hospital and went into work. Police did not say what her job was at the facility.

More from Law&Crime: Dad finds his baby foaming at the mouth and dying inside hot car after he forgot to drop the 7-month-old off at daycare: Cops

At about 3:50 p.m. — nearly nine hours later — someone called 911, saying they found a child in the back seat of a locked car, and though the caller was "banging on the window," they didn't get a response. Officers arrived within three minutes, broke a window, and took the baby out.

"Unfortunately, the baby was deceased at that time," Pauly recounted.

Officers ran a tag on the vehicle and reportedly learned that it belonged to Coleman, who worked at the hospital. They found her, "informed her of the situation, and brought her back to the police department for a formal interview." She was then arrested.

"She forgot," Pauly said of the reasoning Coleman gave for the tragedy. "She was devastated. She was devastated."

The police captain detailed how investigators took a temperature reading of the vehicle about an hour after the child was removed from it. A window was still missing from the vehicle, but the temperature inside was 117 degrees Fahrenheit.

Coleman's other kids were in the custody of their father on Thursday, police added. Pauly said one of the other kids "has some medical needs that require special attention" and that is why Coleman "always chose to take him" into the daycare first.