18-year-old Tiffany Cecconi (pictured, at right, with her daughter; photo courtesy of news4jax.com) was pronounced dead at The Cove subdivision pool off University Blvd. north of Fort Caroline Road. The woman's 18-month-old daughter Kaylani was pronounced dead after being rushed to the hospital.

An 18-year-old male was also rushed to the hospital in serious condition.

"They were all in the pool. We're trying to determine what exactly happened," Lt. Larry Schmitt told reporters. "Quite possibly could be all drowning, but that's what we're trying to determine."

Schmitt says there is no search for suspects and investigators believe the only three people in the water at the time were the three victims.

But one man who helped pull Cecconi from the water isn't sure the mother and daughter drowned.

"Something just didn't seem right," the man told WOKV's news partner Channel 4. "Why was he naked in a pool while she was at the bottom?"

The man, who did not want to be identified, said that man was just standing in the water and didn't respond to anyone around him, including arriving rescue crews. 

"From what I saw, I don't think it could be a drowning," the man added. "How could two people drown when one person who was completely conscious was there?"

"We don't have a lot of details because all the people that were involved in the incident have been transferred to the hospital or are deceased," Jacksonville Sheriff's Office Lt. Larry Schmitt said.

Stay with WOKV for updates to this developing story.