At 2055 Pacific time, the airplane impacted terrain following a loss of control, fatally injuring the non-Instrument-rated Private pilot and three passengers. The airplane was destroyed. Night instrument conditions prevailed. Before takeoff, the pilot received a weather briefing during which VFR was not recommended for his route of flight. After takeoff, the pilot obtained flight following but soon reported having trouble maintaining outside visual contact and controlling the airplane; he requested help getting back to the airport. Controllers attempted to assist the pilot back to the departure airport; however, the radar data depicted the airplane entering a series of turns before radar contact was lost. Weather at the accident site was poor, with rain, mist, fog and low clouds.