On October 18, 2001, at 0940 central daylight time, a Bell 206L-3 helicopter, N348AL, was substantially damaged during a forced landing to the water following a loss of engine power near East Cameron block 78, in the Gulf of Mexico. The helicopter was owned and operated by Air Logistics LLC of New Iberia, Louisiana. The airline transport pilot and two passengers sustained serious injuries, and two passengers sustained minor injuries. Visual meteorological conditions prevailed, and a company visual flight rules (VFR) flight plan was filed for the 14 Code of Federal Regulations Part 135 on-demand air taxi flight. The flight departed the Vermilion 289 platform, Gulf of Mexico, at 0910, with a destination of Creole, Louisiana. The flight originated from Creole at 0733, with 3 passengers, approximately 140 pounds of cargo, and 2.7 hours of fuel for the Vermilion 376 platform. At 0839, the helicopter landed at Vermilion 376, and the three passengers deplaned and their cargo was off loaded. Then four passengers boarded the helicopter, and at 0854, the flight departed for Vermilion 289 for fuel. At 0902, the helicopter landed at Vermilion 289, took on 60 pounds of fuel and departed for Creole. According to the operator, the helicopter was in cruise flight at 500 feet msl, when the pilot heard a "thud," and the helicopter yawed left. The engine lost power, and the pilot initiated an autorotation to the water. The pilot turned the helicopter to the right into the wind and "before the completion of the turn, the hydraulics quit." The helicopter landed "hard" on the water and rolled over. The pilot reported to the operator that he had deployed the emergency floats; however, an examination of the helicopter revealed that the floats had not been inflated. According to the FAA inspector, the wind was reported from the southeast at an estimated 8-10 knots, and the seas state displayed wave heights of three to five feet. An examination of the helicopter, by the FAA inspector, revealed that the fuselage sustained crushing damage to its underside, and the landing skid gear was separated. The vertical fin was separated from the tail boom, and the tail boom was fractured into three pieces. The tail rotor gearbox was separated from the tail boom, and both tail rotor blades were fractured at the doublers. Both main rotor pitch change rods were fractured, and one main rotor blade (yellow) was fractured about three feet out from the hub grip. The mast was bent approximately three fourths of an inch. The other blade (blue) remained attached to the hub assembly. The blue blade displayed chord-wise wrinkles throughout the span of the blade. There was minimum leading edge and chord-wise damage or scraping. According to the helicopter manufacturer's representative, "the damage observed on the main rotor hub and blades is consistent with what would be expected as a result of impact of a slow turning rotor." All three hydraulic servos and the hydraulic pump were removed for testing. The servos and pump were tested at the Bell Helicopter Textron facility, Hurst, Texas, under the supervision of the NTSB investigator-in-charge and no discrepancies were noted. Flight control continuity was confirmed. The Rolls-Royce Allison 250-C30P turbo shaft engine was examined and no signs of a catastrophic failure were found. A pneumatic leak check was performed during the examination and no discrepancies were noted. The fire-shield to fuel nozzle fuel supply line contained no fuel. The contents of the fuel filter was tested and it was determined that the it contained 10 percent fuel and 90 percent sea water. All three fuel cells were empty; however, all three cells were compromised. The fuel control, power turbine governor, fuel pump, bleed valve, and fuel nozzle were tested and found operational.