A 12-year-old girl died and her 9-year-old sister was left in serious but stable condition on Sunday after they were found a half-hour apart, alone and unattended, in waters off Pokai Bay Beach Park.

Beachgoers in the area found the younger girl drifting in and out of consciousness in shallow water and brought her to shore. 

Ocean Safety, Emergency Medical Services and Honolulu Fire Department personnel attended to the girl, who was then transported to an area hospital in serious but stable condition, according to EMS spokeswoman Shayne Enright.

EMS workers used a public address system in their vehicle to locate the girl’s father, Enright said.

It was not known at the time that the girl also had an older sister in the area.

About a half-hour after the initial call, beachgoers spotted the 12-year-old sister submerged in the same area.

Witnesses, including off-duty firefighters, brought the girl to shore and performed CPR until Ocean Safety, EMS and HFD personnel returned to assume care, Enright said.

The girl was transported in extremely critical condition to an area hospital, where she later died.

“Nobody had eyes on this girl,” Enright said. “It’s important that parents understand that we’ve got to watch our children.”