On March 25, 2007 at 0845 central daylight time a single-engine Robinson R22 Beta helicopter, N845WT, was substantially damaged following a loss of power during while maneuvering near Laredo, Texas. The commercial pilot, sole occupant of the helicopter, was not injured. The helicopter was owned and operated by Smith Helicopters, Inc., of Cotulla, Texas. Visual meteorological conditions prevailed and no flight plan was filed for the 14 Code of Federal Regulations Part 91 cattle herding flight. The flight originated from another site within the same ranch at time unknown. The 602-hours commercial helicopter pilot, who reported having accumulated 597-hours in the same make and model helicopter, reported that he was in herding cattle over as small creek at approximately 60 to 75 feet above the ground, when he experienced a loss of engine power. The pilot added that he tried to regain the lost power, but was unable. The pilot entered an autorotation to the rough and uneven terrain. The helicopter touched down on sloping terrain and the helicopter rolled over. The helicopter came to rest on its left side amidst brushes in the sloping terrain. There was no fire. The helicopter had about 12 to 15 gallons of 100 LL aviation fuel on board prior to the start of the cattle herding mission. The helicopter sustained structural damage the airframe and tailboom. Additionally both main rotor blades were destroyed. The landing skids, tail rotor blades and the bubble were also damaged. An FAA inspector examined the wreckage of the helicopter after it was recovered to the operator's maintenance facility. The 2000 model helicopter was reported to have accumulated a total of 1,479.1 hours as of the time of its last 100-hour inspection on January 29, 2007. The pilot reported that he suspected that the loss of engine power was the result of a loss of fuel pressure. The fuel pump was found to be functional when tested on the helicopter. No anomalies were found with the engine that could have prevented normal engine operation. The reason for the reported loss of engine power could not be determined. At 0838, a weather reporting station at Laredo International Airport (LRD), near Laredo Texas, located 14 miles west from the accident site, was reporting wind from 135 degrees at 7 knots, 8 miles visibility, temperature 71 degrees Fahrenheit, dew point 66 degrees Fahrenheit, and a barometric pressure setting of 30.09 inches of Mercury. The investigator-in-charge calculated the density altitude at 1,302 feet at the time of the mishap.