KEYSTONE LAKE, Oklahoma - When people think of drowning, they often picture someone flailing around and screaming. Particularly with children, the moments right before a drowning can be quite and calm and in some tragic cases, you won't know until it's too late. 

A devastating end to a search has left many people's heart broken. Search crews pulled 19-month-old Auri Williams from Keystone Lake Saturday night. 

Investigators say the child wasn't wearing a life jacket when she fell off a raft. The adults pulling the raft told investigators they looked back and didn't see the child. 

"You might turn your back thinking, 'I'll hear from them if they need help,' and you're not going to hear them," said swim instructor Katie Dalrymple. 

Katie has spent the last 15 years teaching water safety. SIt's painful when hearing a child died on the water because it didn't have to happen. 

"It can happen so quickly and they are just under the surface struggling. No one can hear them and in a lake situation, no one can see them," said Dalrymple. 

She says when adults are drowning, they realize they are in trouble faster. Kids may often not recognize the magnitude of the situation and if the adults aren't watching, things can turn tragic fast. 

"Silent. The active drowning phase is completely silent. Somebody in the act of drowning is not able to call for help at all. They will go verticle and their head is under the water," said Dalrymple. 

The pool is a bit different than the lake, but the same rules apply: Always watch your kids and if you're in the lake, always make sure your child is wearing a Coast Guard approved life jacket. 

Keystone Lake doesn't offer this service, but some area lakes offer loaner life jackets. Those can be found at Wolf Creek boat ramp, Twin bridges, State Park at Bernice and State Park at Honey Creek.