The force of an explosion on a boat Saturday near the Sunset Beach marina sent some passengers flying into the water.
The explosion was reported just before noon when a 24-foot powerboat carrying nine people experienced engine troubles shortly after leaving the launch ramp, Huntington Beach Fire Department officials said.
According to the Orange County Sheriff's Department, the explosion was likely caused by a fuel leak in the engine compartment, and when the engine started, it exploded with enough force to throw five of the nine people aboard into the water.
A retired Harbor Patrol officer was nearby and was the first to assist in rescue efforts before emergency responders arrived.
Rescue workers fished the passengers out and rushed eight of them to nearby hospitals with injuries including contusions, lacerations and broken bones.
The explosion was catastrophic to the vessel and caused it to sink.
The official cause is still under investigation.