YULEE, Fla. -

A 9-year-old girl reported to have had a seizure while swimming in a pool Monday was transported to Baptist Nassau but could not be revived, according to the Nassau County Sheriff's Office.

The report said the father called 911 about 12:30 p.m. to report his daughter, Nicole, was not breathing at their home in the Fiddler's Walk subdivision. When a deputy arrived, the victim's sister was performing CPR.  The deputy took over until rescue arrived.

"I could hear rescue getting closer, so I ran with her still cradled in my arms out to the roadway where I met Rescue 20," the deputy wrote in his report.

According to the Sheriff's Office report, the girl had a heartbeat when she arrived at the hospital, but went into cardiac arrest shortly after and could not be revived.

It will be up to the medical examiner to determine whether the girl died of a medical complication or drowned.

A neighbor whose son used to play with the girl was shocked when she heard about her death.

"Healthy and happy and strong; smart little girl. It's just really shocking. Tragic," Rebecca McKinney said. "My heart goes out to her mom and dad and her sister. I can't imagine what they're going through."

Deputies were still investigating the circumstances of the girl's death, Sheriff Bill Leeper said it should remind everyone of the importance of adult supervision around pools.

"In this case, we're not sure that would've saved the individual or not, but that's something you certainly want to do," Leeper said.