Investigators have established that the Porsche Carrera GT Paul Walker and Roger Rodas died in had no mechanical defects before the accident. They also found no evidence of debris or other roadway conditions causing the car to crash and hit a light pole and tree.

The hypothesis that gains more ground is that the car was speeding at the moment of the crash.

“We're looking at speed and speed alone,” a law enforcement official with knowledge of the investigation told the Associated Press. The report says the official was not authorized to speak publicly about the investigation and asked not to be named.

Data recorders survived and may help investigators establish the speed the car carried at the moment of the impact. According to the same official, the Porsche Carrera GT had negotiated a curve in the road just fine before crashing. “They were well out of the curve when they lost control,” the official said.