A 49-year-old Berks County woman died Tuesday after attempting to rescue her three children from “extremely rough" waters at an unguarded beach, officials in North Wildwood said Wednesday.

Her 8- and 10-year-old sons and daughter, 19, were saved by rescue workers and were taken to Cape Regional Medical Center for observation “due to taking in some water,” said North Wildwood Fire Chief Dominick McClain.

He said the rescuers managed to pull them from the water within “10 to 12 minutes” of their arrival.

» READ MORE: Deadly rip currents boost Shore drownings this summer

The incident occurred shortly before 3 p.m. Emergency responders found the woman lying face-down in the water about 150 yards from the shoreline, officials said.

The woman, whose name was not released and was identified only as a resident of Wernersville, was taken to the medical center, where she was pronounced dead, said North Wildwood Police Capt. John A. Stevenson. The official cause of death was not disclosed.

The family had been vacationing in North Wildwood.

» READ MORE: Ocean City searching for missing swimmer, third presumed drowning in a week at the Jersey Shore

It was believed that only one other person was on the beach at the time, said McClain, and with the summer season over, no lifeguards were on duty. Police were alerted by an anonymous 911 call.

On Wednesday the National Weather Service Office in Mount Holly had warned of a “moderate risk” of rip currents due to strong south-to-southeast winds associated with the episodic heavy rains.

“The rip currents were extremely rough, and the waves were crushing,” said McClain.

The incident remains under investigation.