David O’Brien, 24, was reported missing after a boating accident on the San Joaquin River near Antioch, California, on July 1, 2023. He and another man were aboard a 20-foot vessel when O’Brien fell overboard; his companion entered the water to try to rescue him and survived with help from Good Samaritans.

Neither man was wearing a life jacket. The Contra Costa County Sheriff’s Marine Patrol Unit and the U.S. Coast Guard conducted searches, including helicopter aerial searches, but O’Brien was not located and the search was suspended after extensive efforts. Authorities and O’Brien’s family continue to seek answers, and no further developments have been reported.

If anyone was on the San Joaquin River that day or has information about O’Brien’s movements before or during the incident, please come forward.