David Erwin couldn't believe it when he found out 50-year-old Army Colonel James Miller drowned in the sinkhole on his property.
Erwin says Miller's always been prepared and has dived here at least three times.
"I simply couldn't believe it. He's the last person in the world you would ever expect this to happen to," said Erwin.
The Wakulla County Sheriff's Office says Saturday afternoon around four, Miller and two other divers were exploring the Whiskey still sink when Miller dropped a tank at 70 feet.
It was the same tank he needed to survive at 220 feet where he drowned.
"These particular folks our hearts go out to, professionals, because these are true professionals and they've just lost one of their colleagues, said Wakulla County Sheriff David Harvey. "So my heart goes out to them. They were a team."
Now that team is working to be there for Miller's family.
Miller had more than 20 years of dive experience.
Erwin says Miller drowned in the same cave he just recently discovered.