Orlando day care worker charged in death of 3-year-old left in hot van for nearly 12 hours

— -- A Florida day care worker has been charged in the death of a 3-year-old who died after he was allegedly left in a hot van for nearly 12 hours, according to police.

Little Miracles Academy employee Deborah Denise St. Charles, 51, was arrested Thursday and charged with aggravated manslaughter of a child by culpable negligence for the death of Myles Hill, the Orlando Police Department said.

Myles was found unresponsive Monday night inside the vehicle in the parking lot of the Little Miracles Academy in Orlando, police said. The high temperature that day was 93 degrees, according to an arrest affidavit.

On Monday night, 911 dispatchers received a call referencing a deceased child who was found in the back of a 2000 blue Honda Odyssey, according to the affidavit. Myles was pronounced dead nine minutes later, the affidavit states.

About three hours later, St. Charles provided a sworn statement to Orlando Det. Shane Overfield, telling him that she had picked Myles up from her home at 7:42 a.m. that day, according to the affidavit.

During the pickup, Myles' grandmother, Brenda Watts, provided St. Charles with the payment for Myles' childcare and placed him in the back of the van on the driver's side, the affidavit states. Two other children were sitting on the bench seat with Myles, St. Charles told police.

St. Charles then picked up one more child and drove to the Little Miracles Academy's location on West Colonial Drive, according to the affidavit. Once there, St. Charles then exited the van, walked around and opened the van's rear hatch to remove cleaning supplies she was instructed to deliver, she told police.

St. Charles then handed several of the cleaning supplies to some of the children in the van but could not recall to whom, the affidavit states. She then closed the rear hatch of the van and walked into the day care, "assuming all of the children had already entered the business, but [she] admitted to failing to perform a head count to be sure," according to the affidavit.

After turning over the payment for Myles' childcare, St. Charles then left that location and drove to another Little Miracles Academy located on Plymouth Avenue, she told police, according to the affidavit. As she arrived, she received a phone call, and she exited and locked the van "without inspecting the interior," the affidavit states. She then walked into the day care and into her classroom until she left for the day at about 6 p.m.

Myles remained in the van until he was found dead at 8:28 p.m. after Watts notified the day care's owner that he was missing, according to the affidavit.

It is unclear if St. Charles has entered a plea or retained an attorney. She is currently being held at the Orange County Jail on $30,000 bond, according to the jail.

According to the Florida Administrative Code, which governs Florida child care facilities, a driver's log should be maintained for all children being transported in a vehicle. Upon arrival, each child should be marked off the log as they exit the vehicle, and the log should be "immediately" signed and dated.

The code also states that a physical inspection and "visual sweep" should be conducted "to ensure that no child is left in the vehicle," and that a second staffer should also conduct the physical inspection and sign the log.

On Tuesday, the Orlando Police Department executed a search warrant on the day care's Plymouth Avenue location and obtained the logs, which did not comply with the standards required by the state of Florida, the affidavit states. The logs merely showed pickup times and signatures from the child's guardian, and did not include the driver or second employee's signature verifying that they conducted the vehicle sweep, according to the affidavit.

The day care's Plymouth Avenue location is currently listed on Google as permanently closed.

The Orlando Police Department conducted a simulation Wednesday to establish the temperatures the van would have reached on Monday, according to the affidavit. During the simulation, at about 10 a.m., the interior temperature of the van had already increased to 115 degrees, according to the affidavit. By noon, the inside of the van had increased to 133 degrees, and by 3 p.m., it had increased to about 144 degrees.

The Orange County Medical Examiner listed Myles' cause of death as hyperthermia due to environmental exposure, according to the affidavit. The manner of death was deemed to be an accident, the affidavit states.

Myles would have turned 4 on Aug. 22, Orlando Police Chief John Mina said Tuesday.

"Please ensure that we are checking our vehicles for our kids," Mina said, pleading with parents and caregivers. "It just takes a minute."

Friends and family gathered Tuesday night for a prayer vigil in Myles' memory.

ABC News' Emily Shapiro contributed to this report.