The National Transportation Safety Board says water contaminated the fuel tanks of the twin engine plane that crashed on March 16, 2011.
Investigators say the pilot of the Beechcraft turboprop was unable to regain control of the plane after it lost power during takeoff in Long Beach.
The pilot and four other victims were on their way to Salt Lake City for a ski trip.
Those who died include 50-year-old Long Beach developer and owner of the plane, Tom Dean, who lived in Laguna Beach; 51-year-old Ladera Ranch resident Bruce Krall; 49-year-old Jeffrey Berger of Manhattan Beach; and 44-year-old Mark Bixby of Long Beach, a member of the family for which the upscale Long Beach neighborhood of Bixby Knolls is named. The pilot of the plane was identified as 43-year-old Kenneth Cruz of Culver City. Passenger Mike Jensen was the only one to survive the crash.