on the crash. >> reporter: fast cars and high octane driving. the keys of the "fast and furious" franchise. and possibly the cause of death for one of the stars. investigators say they believe the fiery crash that killed paul walker and a friend on saturday involved a single speeding car. his "fast and furious" co-star vin diesel visited the crowd thursday night. >> thank you for coming down here and showing that angel up in heaven how much you appreciate it. >> reporter: omg insider object taped this surveillance video showing in the moment the porsche slammed into a light pole. >> we have confirmed doa. >> reporter: the l.a. county sheriff's department investigate asked ruled out a tip the crash may have been the result of a street race. an eyewitness backs up that conclusion. >> when they passed us, there were no other cars around them