Federal investigators say a small plane's engines were at near full power when it crashed last year in a San Francisco Bay-area neighborhood, killing the three Tesla Motors employees on board.
The National Transportation Safety Board issued a report Friday about the Feb. 17, 2010, crash in East Palo Alto.
The cause may take at least several more months to determine. But the NTSB says the Cessna's engines were running at nearly full power and the propellers were rotating when the plane slammed into an electric tower and power lines.
Investigators used a police gunfire detection system to help determine the engine power.
Two engineers and an electronics manager who worked for Tesla Motors Inc. were killed. No one on the ground was injured.
The plane was operating in fog.