On April 13, 1998, at 1040 eastern daylight time, a McDonnell Douglas 500E, N551CP, operated by the Columbus City Police Department, was substantially damaged during a forced landing to a city street in Columbus, Ohio. The certificated commercial pilot and two passengers were not injured. Visual meteorological conditions prevailed for the public use flight that originated from the Columbus City Heliport in Columbus, Ohio. A company flight plan was filed for the flight conducted under 14 CFR Part 91. In a written statement, the pilot stated he entered a straight-in autorotation to a street after hearing the engine-out horn sound. He also stated that on short final to the intended touchdown point, he identified wires crossing the helicopter's descent path. In an attempt to avoid the wires, he flared the helicopter, trading airspeed for altitude. Then after passing over the wires, the helicopter started to settle. The pilot increased collective and the helicopter touched down tailrotor first. The main-rotor system then flexed down, severing the tailboom causing substantial damage. The engine, an Allison 250C-203 was inspected in the presence of a FAA Representative. Engine continuity was established and no leaks were found with the engine's pneumatic system. A visual inspection of the engine compartment to include the firewall also revealed no anomalies. The fuel system was examined and no evidence of water or other contaminates where found. The helicopter was fueled from a tank at the Columbus Police Department's Heliport. Three other turbine helicopters received fuel from that same tank in the previous 24 hours, and no problems were reported. The helicopter was ground run for approximately 10 minutes, minus the rotor blades because of accident damage. The engine was started and taken to 103%. When the rotor RPM was reduced to 98% the auto-start engaged and the engine-out audio warning was heard. The manufacture ran the engine under load, and it operated to within operational specifications. Further testing was done on the fuel control, engine governor, and engine driven fuel pump. These accessories also where within the manufacture's performance specifications.