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COSTA MESA, Orange County, CA, Sept. 29, 2026 — A crash involving three to four vehicles blocked a southbound lane of I-405 at Bristol Street in Costa Mesa on Monday morning, September 28, according to the California Highway Patrol. At least one person was taken to a hospital.
The California Highway Patrol received a report shortly before 7:45 a.m. describing a white Jeep Patriot, a white sedan and a black sedan involved in a collision just north of Bristol Street. Dispatch logs noted the crash blocked the number two lane and involved as many as four vehicles.
One occupant of the Jeep Patriot was transported to UCI Medical Center in Fountain Valley for treatment, the report shows. No other injuries were detailed in the log, and the extent of the injury has not been released.
A tow company was called to the scene and removed the Jeep Patriot under a vehicle release code, records show. The freeway service patrol that responded to the scene later closed out its portion of the incident. The cause of the crash remains under investigation, and no citations or determination of fault had been released as of this writing.
Our thoughts are with those who were injured, and we wish them a full recovery.
Where Multi-Vehicle Pileups Tend to Start
Chain-reaction crashes involving three or more vehicles cluster in dense freeway segments near major interchanges, like where a highway meets a heavily used arterial, see repeated slowdowns as traffic merges, exits and re-enters within a short stretch of pavement. Drivers approaching from behind often have little warning before traffic ahead has already stopped.
These locations combine high traffic volume with frequent lane changes, since vehicles are jockeying to reach exit or merge lanes at the same time. When one driver brakes hard or a first collision occurs, the vehicles following behind often lack the space or time to stop, and a small incident becomes a multi-car pileup within seconds.
According to the National Highway Traffic Safety Administration, 28,595 large-truck occupants were injured in multi-vehicle crashes involving large trucks in 2023. That figure reflects how quickly a single incident on a busy roadway can pull in additional vehicles and multiply the number of people hurt.
Frequently Asked Questions
What makes multi-vehicle crashes difficult to investigate?
Investigators often have to determine the order in which vehicles collided and how each impact contributed to the damage and injuries. With several drivers and witnesses involved, accounts can vary, and reconstructing the sequence takes time.
What typically causes chain-reaction crashes?
They usually start with one vehicle slowing or stopping unexpectedly, often due to congestion, a hazard in the roadway or an earlier collision. Vehicles following too closely or unable to react in time then strike one another in succession.
How can drivers avoid getting caught in a pileup?
Keeping a longer following distance, watching brake lights well ahead rather than just the car directly in front, and reducing speed in heavy or merging traffic all give drivers more time to react if traffic ahead stops suddenly.
What to Do After a Multi-Vehicle Crash in Costa Mesa, CA
If you're involved in a crash with multiple vehicles, try to move to a safe location if your car is drivable and it's safe to do so, then turn on hazard lights to warn oncoming traffic. Check yourself and any passengers for injuries before checking on others nearby.
Even if you feel fine, it's worth getting checked by a medical professional, since some injuries, like whiplash or internal bruising, aren't obvious right away. Exchange information with the other drivers involved and take photos of the scene, vehicle positions and any visible damage if you're able to safely do so.
Filing a report with local authorities and keeping a copy for your own records can help later, especially in a crash with several vehicles where fault may take time to sort out.
