Alley, 26, reportedly crashed his car against a guardrail near a riverbank at around 5 a.m. Saturday. When police arrived, they found the wrecked vehicle, but there was no sign of the driver, said Pensacola assistant police Chief Chip Simmons. Alley's keys, cell phone and wallet were left in the locked car.

Alley moved from Salt Lake City to Florida for training at Whiting Field Air Force Base. He lived in Florida with his wife, who is four months pregnant.

Alley's family launched a rescue effort, searching on ground and putting up fliers with the help of their LDS ward in Pensacola, according to the Web site they set up, http://helpfindjohn.info. Alley's brother, Luke Alley, who is a student at BYU-Idaho, also created a group dedicated to finding his brother on the networking site Facebook.

The search came to an end when a fisherman spotted a body washed ashore Monday morning. Simmons said police are 99 percent sure the body is Alley because of the green flight suit he was last seen wearing. An autopsy has been scheduled to assure the body's identify.

Simmons said there was no sign of foul play.

Efforts to reach the family were unsuccessful. A fund to help the family has been created through the Web site, where they have also thanked the community for searching.

"We wish to express appreciation to everyone who has helped us and are helping at this difficult time," his family writes on the Web site. "The outpouring of love and kindness has been overwhelming. We love John and will dearly miss his amazing spirit, but are grateful for the knowledge of where he's at and that we'll see him again."