*Update* Swimmer pulled from Lake Travis dies

*Update* Travis County Sheriff's officials say the young woman who was hospitalized after she went under at Windy Point in Bob Wentz Park has died.

Authorities have identified the victim as 18-year-old Sylvia Koffa of Austin.

This is an update to a previous story, The original version is as follows:

A young woman from Austin is in the hospital after nearly drowning in Lake Travis. First responders were able to find her after she went under at Windy Point in Bob Wentz Park. 

They pulled her to shore and spent seventeen minutes reviving her. According to EMS, she was taken to St. David's Round Rock Medical Center aboard STARflight. Her condition is unknown at this time. 

"Her family and some other witnesses saw her struggling at the surface, they went to try to help her, she went under they weren't able to get to her and they called 911", says Travis County Sheriff's Deputy Sergeant John Loughran.

The 911 call came in around 1:45. Travis County Deputies, EMS, and Fire were on scene by 1:52 and divers in the water by 1:57 Loughran.

The family was able to give first responders an accurate location of where the swimmer was last seen fifteen feet from the shore. Something that helped divers to immediately find her. 

"If you should find yourself in a situation like today where someone is in distress, we would like to have the bystanders take mental notes," says Austin Travis County EMS Captain Darren Noak. Adding, "if they are able to provide a very accurate point last seen that obviously decreases the amount of time that rescuers take to locate these victims."

Sisters Cheryl and Stephanie Rhemann were enjoying a day at the lake with their kids when the swimmer went under. "I've been coming out here since i was a baby with my parents," Cheryl says they spent July 4th there too. She went swimming around where the teen was last seen. "That area it's really rocky you could hit your head."

How or why the swimmer went under hasn't been released yet.  But she was found 15 feet under water and pulled to the shore where EMS started CPR. They say it took 17 minutes to revive her.

"We are typically going to work a person in the range, of course the situation varies , but in the range of 20 minutes," Captain Noak says of similar situations.

Sergeant Loughran said the response was swift, "it was very tense, you have family and friends," and he added commending his fellow first responders by adding, "EMS and fire they are the best at what they do."

It's not clear if she ever regained consciousness but she remains hospitalized. 

Captain Noak describes the body's response to a lack of oxygen. "Typically as a general rule of thumb in the 4-6 minute range is where brain cells begin to die off," he says adding, typically about 10 minutes with lack of oxygen those cells no longer function."

First responders say the teen was a good swimmer but Sergeant Loughran warns you can never take enough precautions. "Lake Travis is a dangerous lake, it's a dark lake, the water isn't very clear."

A danger the Rhemann sisters won't soon forget. Says Cheryl, "It's a big concern, you just have to keep a close eye watching them," of her children swimming in the shallow waters. Her sister Stephanie adding, "It's a tough day for the family I'm sure, it's really really sad."

Lake Travis Fire Rescue offers free CPR classes for those interested.