The official told AP that the Porsche appeared to have negotiated a curve in the road successfully before crashing.

"They were well out of the curve when they lost control," the official said.

Investigators with the Los Angeles County Sheriff's Department have calculated a range of the speed at which they think the car was traveling, but they won't firm up that number until Porsche engineers come to California next month in the hope of extracting information from onboard data collectors.

The official would not disclose the current speed estimate. It is calculated through a formula that uses factors including the arc of tire marks from the scene and how well the tires would grip the roadway, said Chris Kauderer, chairman of the California Association of Accident Reconstruction Specialists.
Highway Patrol accident reconstruction specialists, who tested the brakes on the wrecked car and found that at least one of the tires was made in 2004.