One of two Red Deer area children who fell through the ice Friday morning has passed away.

Red Deer RCMP said they were called to a rural property southwest of Red Deer at about 10:20 am Friday.

Police said family members had found two girls, sisters aged 3 and 5, had fallen through the ice on a pond on the property.

"Family members immediately requested assistance, and both these little girls were transported to the Red Deer Hospital," RCMP spokesperson Doris Stapleton said.

The two girls were then taken to the Stollery Children's Hospital, but a source tells CTV News that the youngest girl did not survive the night. There has been no update on the condition of the 5-year-old.

Police believe the incident was an accident. They say it should serve as a warning, because temperatures are rising, ice is thinning, and is becoming unsafe.

"We've had some warm weather," Stapleton said. "The ice has become thin and fragile. Please be careful."

With files from Sean Amato & Amanda Anderson