A 4-year-old girl and a 2-year-old boy died after being swept away by a creek in San Bernardino County on Tuesday, authorities said.

SAN BERNARDINO COUNTY (KABC) – A 4-year-old girl and a 2-year-old boy died after being swept away by a creek in San Bernardino County on Tuesday, authorities said.

The incident occurred at the Thurman Flats picnic area, west of Mountain Home Village.

The San Bernardino County Fire Department said they received a call from the girl’s mother saying the little girl went to Mill Creek and was swept away.

The mother reportedly told her two-year-old son to stay where he was while she went to look for her daughter. Authorities said it took the mother about an hour to call 911 because there was limited cell service in the area.

When she returned to the crime scene, the boy had already disappeared.

Firefighters initially found the girl who was underwater and took her to a local hospital. Shortly afterwards they found the boy.

Authorities said the girl was taken by ambulance to Redlands Community Hospital while the boy was flown by plane to Loma Linda University Medical Center.

They were pronounced dead later that evening.

This is a developing story. This article will continue to be updated as more information becomes available.