He hit the water, and just didn't come back up.
"I saw him hit the water. I sawÂ the splash," said Dennis Fay, a friend and neighbor of the young man's family.
It was how the 21-year-old hit the water that shocked everyone who was watching.
"He was doing his flips,Â he landed face first," said Sacramento County Sheriff'sÂ Deputy Mark Warren.
It's a trick the 21-year-old had done before, but this time he climbing up toÂ a taller piling besides the dock where his family kept their boat at Walnut Grove Marina. It's a piling 40 feet above water level.
And even though his family told him not to, he tried his trick dive from them from the new height.
"I talked to him earlier today, and he was just a nice young guy," Fay said. "Straight laced, not drinking or drugging or anything, just having fun. And then something like this happens."
Family members jumped-in after him right away. But no luck. Hours later boats, and helicopters and divers would still be searching the water.
"The water's prettyÂ murky in this area," Deputy Warren said.
But then, just before sundown, the news everyone knew was coming, but no one wanted to get.
The Sacramento County Coroner will identify the young man, and they will determine for certain what killed him.Â The working theory among rescue crews is that the wind was knocked out of him when he hit the water and he couldn't save himself. But deputies said, from that height, the force of the impact at the wrong angle might have broken his neck.