The pilot departed with three passengers and three dogs, but only two seats. The airplane had been reconfigured (STC SA00352DE) for parachute jumping operations. The STC included the stipulation that the airplane could be used only for parachutist launching operations. Also, Title 14 CFR Part 91.107, (a)(3), states that each occupant of a civil aircraft must be provided with an approved seat [the fatally injured passenger was not] with seat belt, for movement on the surface, takeoff, and landing operations.
After discharging sky divers, plt was concentrating on max rate of descent, eng pwr at idle, when fuel tank in use ran day. Pwr loss not noted until throttle applied for level off. Switch to usable fuel tank and restart attempt initiated with insufficient remaining altitude for successful result. Forced landing executed on freeway off ramp.