A CHP investigation into the fatal collision that killed a Petaluma woman at a Camp Meeker conference center remained underway Monday, the CHP reported.
An inspection of the Mercedes involved in the Feb. 24 crash was expected to be done later this week, said CHP spokesman Officer Jon Sloat.
Investigators still are attempting to calculate the speed of the Mercedes when it launched off of Bohemian Highway and into a parking lot below.
The car smashed into a gazebo where Petaluma resident Nola Mary Wolf, 61, sat with her husband and others. They were at the Alliance Redwoods Conference Grounds outside Camp Meeker for a tree canopy zipline tour.
The impact killed Wolf and carried her at least 75 feet into a nearby creek bed.
Driver Johnella Thomas, 74, of San Francisco told officers she believed her brakes failed.
"The driver simply stated her brakes didn't work and the car suddenly accelerated," said Sloat.
Investigators will look for mechanical failure on the 2010 Mercedes. The other possibility is driver error, that Thomas stepped on the gas pedal, believing it was the brake.
If officers determine the cause of the crash was driver error, Thomas could face an arrest on suspicion of involuntary manslaughter.
The investigation has ruled out, at least preliminarily, that Thomas suffered a medical crisis.
A witness had estimated the car was going 70 mph before it drove off of the rural, winding highway.
Investigators were hoping to determine the speed based on how far the car traveled.
It flew more than a few hundred feet before coming to a stop in the creek bed.
Thomas was seriously injured and was treated at Santa Rosa Memorial Hospital. The hospital Monday had no information on her status.
Her passenger, Lillie Richardson, 76, of Marin City, also had been injured and treated at Memorial. Her condition wasn't available Monday morning.
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