Two 2-year-old children were found dead inside a car in Oklahoma last week, according to police.

The toddlers were discovered by Norman, Oklahoma, police officers conducting a welfare check on Thursday afternoon, a news release said. The children were inside a vehicle on the street in a neighborhood in Norman, about 20 miles from Oklahoma City. Per the Weather Channel, temperatures were about 90 degrees that day.

An initial investigation found that the 2-year-olds were accidentally left in the vehicle for "an extended period of time" and were later located by family, the release said.

The investigation is ongoing, and the medical examiner will determine the cause of death.

USA TODAY reached out to the Norman Police Department for more information.

Hot car deaths:2-year-old dies after being left in a hot car in New York. It’s the 12th US case in 2024.

'The best girls'

Local news stations identified the toddlers as twin girls named Ariel and Avery.

Investigators said a family member was supposed to take the girls to daycare but accidentally left them, KFOR reported. It's unclear whether the family member was charged.

“They were the best girls the world has ever seen," their father, Marshall Suter, told the outlet. "It honestly hurts because the girls were so deeply loved and cared for."

GoFundMe set up for family

A GoFundMe was set up by a family member to help with the funeral cost "and take some weight off of this father’s shoulders after dealing with such a tragic and heartbreaking loss," the fundraiser said.

"No one truly knows the pain of losing a child until you are going through it. I know this mom and dad are going through it," the caption continued.

As of Tuesday morning, the fundraiser exceeded its goal with nearly $11,000 raised.

Hot car deaths

Several children around the country have died this summer due to hot car-related accidents. The incidents occur the most between May and September as the weather is warmer.

Expert David Diamond PhD, a Florida-based psychology professor, told Consumer Reports that forgetting a child in a car could happen to anyone, explaining that it's less of a negligence concern and more of a "memory problem."

Tips for preventing such a tragedy include making a habit of opening the rear door as you get out of the car and asking child care providers to call if your child isn't dropped off as scheduled.

Taylor Ardrey is a news reporter for USA TODAY. You can reach her at [email protected].