A serious multi-vehicle collision on U.S. Highway 101 in Petaluma, California, caused major traffic disruptions Saturday afternoon after authorities temporarily closed all southbound lanes near the East Washington Street interchange.
According to the California Highway Patrol (CHP), the crash was reported shortly after 1:10 p.m. on southbound Highway 101 just north of East Washington Street. Emergency responders rushed to the scene after receiving reports of a collision involving at least two vehicles along the heavily traveled Sonoma County corridor.
Firefighters, paramedics, and CHP officers arrived within minutes and began securing the area while assessing those involved. Witnesses described a significant emergency response, with numerous police vehicles, fire engines, and ambulances converging on the crash site.
Major Traffic Delays Across Petaluma
As emergency crews worked to assist victims and investigate the collision, authorities shut down all southbound lanes of Highway 101 near the interchange. The closure quickly led to severe traffic backups stretching for miles, impacting weekend travelers, commercial vehicles, and local residents throughout the Petaluma area.
Drivers were advised to avoid the area and use alternate routes while crews cleared damaged vehicles and documented the scene. Nearby surface streets also experienced heavy congestion as motorists sought detours around the freeway closure.
The shutdown affected one of Northern California’s busiest transportation corridors, where even minor incidents can create widespread delays due to high traffic volumes and limited alternative routes.
Investigation Underway
Officials have not yet released information regarding the number of people involved or the extent of injuries sustained in the crash. Authorities also have not confirmed whether any fatalities occurred.
Investigators are examining all possible contributing factors, including roadway conditions, driver actions, vehicle performance, and other circumstances that may have led to the collision. Evidence collected from the scene, including vehicle positions, roadway markings, and witness statements, will be analyzed as part of the ongoing investigation.
Traffic camera footage from the area may also be reviewed to help reconstruct the events leading up to the crash.
Lanes Reopen as Cleanup Concludes
After several hours of emergency operations and vehicle removal efforts, authorities gradually reopened the affected lanes and traffic slowly began returning to normal later in the afternoon. However, residual delays continued into the evening as congestion worked its way through the region.
The California Highway Patrol is continuing its investigation and is asking anyone who witnessed the crash or has relevant information to contact investigators.
Additional details, including confirmed injury information and the cause of the collision, are expected to be released once authorities complete their preliminary review.