"All I remember was that he said he broke his neck and he said he was scared," Asaih recalled Wednesday, several days after the accident. "I had a little time limit in my head. If I jump in and the person I'm jumping with in that certain amount of time (doesn't come up), I go after them."

Asaih never took any true technical swim training — he just knew something went terribly wrong at that moment and he was the only person in a position to help.

The crucial moment came at the end of a relaxing day at Quietwater Beach for the Pensacola family of five on Saturday. The Williams family had just spent all day swimming and relaxing when, shortly after sunset, Asaih convinced his dad, Josh, to take one last dip before calling it a night.