David O’Brien, 24, was reported missing on July 1, 2023, after a boating accident near Antioch, California. O’Brien and another man were aboard a 20-foot vessel on the San Joaquin River when O’Brien fell overboard. His companion jumped in to try to rescue him, but O’Brien was not found. Neither man was wearing a life jacket at the time of the incident. Despite efforts by the Contra Costa County Sheriff's Marine Patrol Unit and the U.S.
Coast Guard, including aerial searches by helicopter, O’Brien was not located, and the search was eventually suspended after extensive efforts failed to recover him.
The search began immediately after the incident, with Good Samaritans helping the other man, who survived. Authorities and O'Brien’s family continue to seek answers, but no further developments have been reported since the search efforts.Last Seen: Jul 1, 2023