CBS Atlanta is asking Tough Questions after a young girl died the Chattahoochee.
On Friday from CBS Atlanta's sky eye camera you could see rescue boats race to help 9-year-old Anna Van Horn.
Van Horn fell into the water afetr tubing with friends.
"It unfortunately was a fatality. She died at the hospital," said Capt. Jason Shivers, Forsyth County Fire Department.
CBS Atlanta learned almost two hours before crews were called to the rescue, the Buford Dam was opened and water was released for a few hours.
"Prior to a water release sirens activate, warning everyone to get off the river immediately," said Shivers.
The sirens sound from the dam to the Georgia Highway 20 Bridge for three-and-a-half minutes. After that, for a half hour the sirens sound 10 times.
Shivers said Van Horn was found a half mile out of this stretch.
The Tough Questions: Was Van Horn too far away to hear the siren? And did she have enough time to get out of the water?
"I don't know. It just depends on the time of year, the foliage coverage, the sound of traffic, the flow of water. You are talking about a 9-year-old-girl. Who's to say she would know what the sirens mean anyway," answered Shivers.
Van Horn was wearing her life jacket. It's still a mystery how she died.
To find out when water is released, call the water release line or listen to the radio.
For all that information log onto: http://lanier.sam.usace.army.mil/WaterSafety.htm