All three people on-board died that day and the weather was the reason for the controller's concern. The fog was especially dense on the Peninsula, the morning of Feb.17, 2010.
On Tuesday night, ABC7's media partners at the San Jose Mercury News made public audio recordings that they obtained from the Federal Aviation Administration.
"We have your release. The runway's not visible so it's at your own risk," said the air traffic controller. Roughly, 30 seconds later, the tower repeated a second warning. "I cannot clear you for takeoff because I don't have visibility on the runway, so the release is all yours and it's at your own risk, sir."
The twin-engine Cessna plane took off anyway and crashed into a residential neighborhood after hitting an electrical tower.
The pilot and two employees from Tesla Motors died.
ABC7 aviation consultant Ron Wilson has heard the tapes and said that in an extremely foggy situation air traffic controllers only work in an advisory role.
"Certainly, the air traffic controller, you can't slight him for this. It was on the shoulders of the pilot of that aircraft and he decided to take off in conditions that were less than advisable," said Wilson.
The tapes also show that the plane's departure time was a half hour later than scheduled, but it's not clear if the delay might have caused the pilot to feel rushed.
The plane was headed to a Tesla meeting in Southern California.