Two young Comanche County girls died Friday after they were trapped inside a hot vehicle.

CACHE (OK) - Paramedics were called to a rural home south of Cache about 2:45 p.m. Friday, Comanche County Undersheriff John Stowe said. A caller told dispatchers the girls, ages 5 and 6, were not breathing.

They were pronounced dead on arrival at Comanche County Memorial Hospital, Stowe said.

"Somehow they got locked inside," Stowe said. "We are still trying to figure out how."

A woman who discovered the girls broke out a window in the vehicle and performed CPR on them until paramedics arrived, Stowe said.

The girls were taken to the medical examiner's office in Oklahoma City so an official cause of death can be determined.

"I really don't have words to express this," Stowe said. "This is a tragedy. The relatives have got to be feeling intense grief."

Stowe said authorities are waiting to notify the girls' next of kin before releasing their names. He would not name the family.

The incident marked the second and third children to die this summer in Oklahoma after being left unattended in a hot car, said Jan Null, a meteorology consultant and adjunct professor at San Francisco State University. Nationwide, 10 children have died in hot cars this summer, including the two Oklahoma girls, Null said.

Null said the temperature inside a car parked in the sun can rise almost 20 degrees in the first 10 minutes and temperatures inside can climb to more than 140 degrees in an hour. Children's bodies are not as well suited to deal with the stress from the heat as adults, he said.

"It doesn't take a child's body long to reach lethal temperatures," Null said.

By Ron Jackson and Josh Rabe
The Oklahoman